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NP1550 

SERVICE 

MANUAL 



COPYRIGHT CANON INC. 
PRINTED IN IAPAN 



Canon 
FY8-13BN-010 



I GENERAL DESCRIPTION I 



I. FEATURES 

1 . Copies as large as A3 in size (DIRECT) may be made, and the copyboard is of a fixed type. 

• Although compact in design the copier enables making copies as large as A3 in size in the 
DIRECT mode. 

• The copyboard is of a fixed type so that pages of a book may be copied with much ease. 

2. Zooming between 50% and 200%. 

• Copies may be made in reproduction rations of between 50% and 200%, selectable in 1% 
increments. 

3. Front loading for faster supply of paper. 

• Paper is loaded from the front of the copier so that the cassette may be replenished with 
paper without wasting time. The design also saves space. 

4. Single component fine particle toner for high resolution. 

• Copies are developed using the single component toner projection method. Further, the 
copier uses toner of extremely fine particles for enhanced image quality. 

5. Multifeeder (stack bypass) pick-up. 

• As many as 50 copies (80 g/rri) may be made continuously using the multifeeding 
mechanism. 



COPYRIGHT© 1992 CANON INC. CANON NP-1550 REM JAN. 1992 PRINTED IN JAPAN (IMPRIMEAUJAPON) 1-1 



I GENERAL DESCRIPTION I 



II. SPECIFICATIONS 

A. Type 



Body 


Desktop 


Copyboard 


Fixed 


Light sourse 


Halogen lamp (300W) 


Lens 


Zoom lens : 


Photosensitive medium 


OPC 



B. System 



Reproduction 


Indirect electrostatic method 


Charging 


Corona 


Exposure 


Slit (moving light source) 


Copy density adjustment 


Auto or Manual 


Development 


Dry 


Pick-up 


Automatic 


Exclusive cassette 


Manual 


Multifeed 


Transfer 


Corona 


Separation 


Curvature and Static eliminator 


Drum cleaning 


Blade 


Fixing 


Heat roller (900W) 



C. Performance 



Type of document 


Sheet,Book,3-D object(2 kg) 


Document size 


A3 max. 


Wait time 


75sec(approx.;at20°C) 


First copy 


9.4 sec (A4, AE ON/OFF, 1:1) 


Continuous copying 


99 copies 


Copy size 


A3(max.),A6(min,;148x105 mm) 


Type of 

copy 

paper 


Cassette 


Plain paper(64 to 80 g/m 2 ),Tracing paper, 
Colored paper 


Multifeed tray 


Plain paper(64 to 128 g/m 2 ), Tracing paper*, Colored 
paper, OHP film*, Postcard, Label sheet 



*Use of tracing paper may cause double feeding. If thin paper or OHP film, feed one sheet at a time. 



1 -2 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.O JAN.1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



I GENERAL DESCRIPTION I 



Two-sided 
copying 


Multifeed tray 


Plain paper(64 to 1 28 g/m 2 ), Colored paper, Postcard 


Overlay 
copying 


Multifeed tray 


Plain paper(64 to 128 g/m 2 ), Colored paper, Postcard 


Cassette 


Claw 


Provided. 


Standard 


27 mm deep( about 250 sheets of 80 g/m 2 paper) 


Universal 


None. 


Copy tray 


100 sheets(approx.; A4, 80 g/m 2 ) 


Non-image 
width 
(1st side) 


Leading edge 


2.0 ±1.5 mm or less 


Left/Right 


2.5 ±1 .5 mm or less 


Auto clear 


Provided. (2 min, standard) 


Auto shutoff 


None. 


Option 


ADF-A1 , CT unit, MS-A1 , Stapler Sorter-B1 , CC-V 



D. Others 



Power 
supply 


_^_— " 


Serial Numbers 


220V 50Hz 


UBN XXXXX 


240V 50Hz 


QBN XXXXX 


Power 
con- 
sumption 


Maximum 


1 .5kW or less 


Standby 


0.1 48 kWh (Reference value) 


Continuous copying 


0.64 kWh (Reference value) 


Noise 


Copying 


55dB or less 


(sound power level 
as prescribed by ISO) 


Standby 


40dB or less 


Ozone 


0.05ppm or less (UL standards.) 


Di- 
mensions 


Width 


697mm 


Depth 


617mm 


Height 


391mm 


Weight 


50.6kg 


Operating 
environ- 
ment 


Temperature 


15.0°Cto30.0°C 


Humidity 


5% to 80% 


Atmospheric pressure 


0.6 to 1 


Others 


Keep copy paper wrapped to protect against moisture. 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.0 JAN. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



1 -3 



I GENERAL DESCRIPTION I 



Reproduction mode 


Paper size 


Cassette 


Copies/min 


DIRECT 


A3 (297x420mm) 


A3 


9 


A4 (210x297mm) 


A4 


15 


B4 (257x365mm) 


B4 


10 


B5 (182x257mm) 


B5 


17 


A5R (210x149mm) 


A5R 


16 


REDUCE 


I 


50% 




^^^ 


II 


A3^A4 


A4R 


10 


ENLARGE 


I 


A4-A3 


A3 


9 


II 


200% 


^^ 


^^^ 



1 -4 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.0 JAN. 1992 PRINTED IN JAPAN (IMPRIIIE All JAPON) 



I GENERAL DESCRIPTION I 



III. NAMES OF PARTS 

A. External View 

(D -© ® 




© Copy tray 

© Copyboard cover 

@ Control panel 

@ Power switch 

© Cassette 

© Delivery cover 



Figure 1-1 




© Copyboard glass 
© Multifeeder cover 
© Multifeeder tray 
© Developing assembly 

release lever 
© Feeder assembly release 

lever 
© Drum unit 
© Fixing assembly knob 



COPYRIGHT© 1992 CANON INC. 



CANON NP-15S0 REM JAN.1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



1 -5 



I GENERAL DESCRIPTION I 



B. Cross Section 

© © ® © . © 




© No. 3 mirror 

© No. 2 mirror 

(3) No. 1 mirror 

® Scanning lamp 

© Copyboard glass 

© Copyboard cover 

© Lens 

® Pre-exposure lamp 

© Primary corona assembly 



) No. 6 mirror 

) No. 5 mirror 

) No. 4 mirror 

) Multifeeder tray 

) Developing assembly 

) Feeder roller 1 

) Registration roller 

) Pick-up roller 

) Feeder roller 2 

Figure 1-3 



& Transfer corona assembly 

( Photosensitive drum 

) Cassette 

) Feeder assembly 

) Exhaust fan 

) Fixing assembly 

) Delivery roller 



1 -6 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



I GENERAL DESCRIPTION I 



IV. OPERATION 

A. Control Panel 



© © 

(D © 




Figure 1-4 



©SORT/GROUP key 

Press it to select the sort, group, or non- 
sort mode. The indicator remains unit 
when the non-sort mode is selected. 
^- sorting 
2- grouping 

© PAGE SEPARATION key 

Press it to select the page separation 
mode. 

(D JAM indicator 

® CONTROL CARD indicator 

© ADD PAPER indicator 

© ADD TONER indicator 

© COPY COUNT/RATIO indicator 

It indicates the reproduction ratio when 
the % key is pressed. 

® COPY START key 

• glows orange when the copier is not 
ready for copying. 

• glows green when the copier is ready 
for copying. 

® RESET key 

Press it to reset the copier to its default 

settings. 

Default Settings 

• copy count 1 

• DIRECT 

• AE (may be turned OFF using 'C15' of 
service mode) 

• non-sort 



» CLEAR/STOP key 
) STANDBY key 
) NUMERIC keypad 
» % key 

Press it to check the reproduction ratio 

using the copy count indicator. 

The display changes to the copy count 2 

sec after the key is released. 
) ZOOM key "■ 

Press it to select desired reproduction 

ratios between 50% and 200% in 1% 

increments. 
D AUTO RATIO key 

Press it to select or deselect the auto 

reproduction ratio mode.; 

The key is effective when the ADF is attached. 
i PAPER SELECT key 

Press it to select the cassette or multifeeder 

as the source of paper. 
) PAPER SELECT/JAM indicator 

A LED goes ON to indicate the location of 

the paper or flashes to indicate the location 

of the jam, if any. 
D ENLARGE key 
I DIRECT key 
J REDUCE key 

D AE (automatic exposure (density) adjust- 
ment) key 
D COPY DENSITY lever 



COPYRIGHT© 1992 CANONINC. 



CANON NP-1550 REV.1 SEPT. 199! PRINTED IN JAPAN (IMPRIME All JAPON) 



1 -7 



I GENERAL DESCRIPTION I 



B. Basic Copying Operation 

1 ) Set the power switch to ON (I). 

a) If the temperature of the fixing roller is 
too low for copying, the indicator of 
the COPY START key will blink green. 

b) When the temperature of the fixing 
roller becomes high enough for 
copying, the indicator will glow green. 

c) The normal waiting time at room 
temperature (20*C) is about ,75 
seconds. 

2) Raise the copyboard cover, place an 
original on the copyboard with the side to 
be copied facing downward, and align it 
with the size indication. 

3) To adjust the copy density manually, the 
AE key indicator should be OFF; press 
the key once if it is ON. Set the COPY 
DENSITY lever to suit the original. 

4) Check the size of paper in the cassette, 
a) If the cassette does not have the 

desired size of paper, remove it and 
install a cassette with the desired 
size. 

5) Set the required number of copies (1 to 
99) using the NUMERIC keypad and 
confirm that the correct number appears 
on the COPY COUNT/RATIO indicator, 
a) If an error was made in inputting the 

number of copies, press the 
CLEAR/STOP key and reset the 
number of copies. 

6) Press the COPY START key 

a) To stop a continuous copying operation, 
press the CLEAR/STOP key or RESET 
key. The copier will complete the copy in 
progress, then stop. 

The COPY COUNT/RATIO indicator 
will display the initially set copy 
quantity. 

b) It is possible to switch from automatic 
exposure control to manual density 
adjustment at any time from the start of 
copying to the completion of the final 
copy. However, it is not possible to 
switch from manual density adjustment 
to automatic. 



Example: 

If the copy is too dark or too faint using AE, 
cancel AE and vary the copy density with the 
COPY DENSITY lever. 

c) If the ADD PAPER indicator goes ON 
during copying, the copier will stop. 
Refill the cassette and press the COPY 
START key. The remaining number of 
copies will be made automatically. 

d) If the copier has a ADF, place a document 

(original) on the document tray. The 
document will be fed automatically and 
copying will start. 

e) If ^no other operation is performed, the 
copier will return to the STANDARD 
mode approximately 2 minutes after it 
completes a copy or after the last key 
operation. 

C. PiCk-Up from Multifeeder 

1 ) Set documents on the copyboard. 

2) Press the PAPER SELECT key to select 
the multifeeder. 

3) Open the multifeeder tray. 

4) Open the multifeeder cover. 

5) Set the slide guide to the size of the copy 
paper. 

6) Set copy paper. 

• As may as 50 sheets (80 g/m) may be 

set: 
Close the multifeeder cover. 
Set the desired reproduction ratio using 
the DIRECT, REDUCE, ENLARGE, or 
ZOOM key. 

Cancel the AE mode, and set the COPY 
DENSITY lever if manual adjustment of 
the density is desired. 

10) Enter the number of copies using the 
NUMERIC keypad. 

11) Press the COPY START key. 



7) 
8) 



9) 



1 -8 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



I GENERAL DESCRIPTION I 



D. Two-Sided Copying 

Copy one side of a 2-sided original. 
Invert the original so that the same edge 
faces the front. > Invert the copy in the same 
way (front edge facing the front) and feed it 
into the copier. 

a) Use dry, uncurled paper. 

b) Use paper in the weight range 60 to 
128g/rri 

c) When making two-sided copies, only 
one image can be made on each 
side of the copy paper. 

d) Both overlay and two-sided copies 
cannot be made on the same sheet 
of copy paper. 



Back edge 



Front edge 



01=1 



Back edge 






Front edge 



Figure 1-5 



E. Overlay Copy Operation 

By changing the developing assembly, a 
2-color copy can be made on the same side 
of the copy paper. 

a) Use paper in the range of 60 to 1 28 g/m 

b) When making an overlay copy a 
maximum of two images can be 
made on one side of the copy paper. 

c) Overlay and two-sided copies cannot 
be made on the same sheet of copy 
paper. 

F. Autostart 

The auto start mechanism may be made 
use of while the copier is in the wait mode 
(COPY START key blinking green); i.e., after 
it is switched ON or after the standby mode 
is cancelled. 

Set a document while the copier is in the 
wait mode, and select the copy mode; then, 
press the COPY START key. 



The COPY START key changes from 
blinking green to orange to indicate that the 
auto start mechanism has been activated. 

The copier starts making copies as soon 
as it enters the standby mode using the 
selected copy modes. 

The auto start mechanism may be can- 
celled by pressing the CLEAR/STOP or 
RESET key. ; 

G. Replacing the CT Unit 

1 ) Open the front door. 

2) Swing the developing assembly release 
lever counterclockwise. 

3) Pull the developing assembly forward. 

4) Grasp the handle of the developing 
assembly, and gently raise it. 




Figure 1-6 



5) Place the CT unit gently on the develop- 
ing assembly guide rails and push it in 
the copier. 

6) Shift the developing assembly release 
lever clockwise until it is horizontal. 

7) Close the front door. 

i. Do not tilt or handle the developing 

assembly or the CT unit roughly, 
ii. Do not place the developing assembly 

'■i •-•^p^W^'^W^W*^* box or in 
the pedestal of the copier. 



COPYRIGHT© (992 CANON INC. 



CANON NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IUPRHIE AU JAPON) 



1 -9 



I GENERAL DESCRIPTION I 




V. WARNING INDICATOR AND 
REQUIRED ACTION 

A. JAM Indicator sV 

If an area of this indicator flashes while 
copying is taking place, it is likely that the 
paper has jammed at the position represent- 
ed by the part that is flashing. Check and 
take action as follows. 



ADF unit document JAM indicator 
Copier paper JAM indicator 

Right door OPEN indicator 
Cassette OUT indicator 
Sorter JAM indicator 

Figure 1-7 



When clearing a paper jam which has 
occurred in an option unit (sorter or ADF), refer 
to the Service Manual for the option unit. 

• ADF unit document JAM indicator 

• Copier paper JAM indicator 

• Right door OPEN indicator 

• Cassette OUT indicator 

• Sorter JAM indicator 

If paper jams inside the copier, check the 
paper pick-up area, separation feeder area, 
fixing/copy delivery area, and cartridge area; 
and remove all jammed paper. 

1 ) Open the front door. 

2) Remove the copies from the copy tray. 

3) Operate the release and open the copy 
delivery assembly. 

4) Check if there is copy paper jammed in 
the fixing assembly. If there is paper jam 
in it, turn the knob of the fixing rollers 
clockwise to remove the jammed paper. 




5) Close the copy delivery assembly. 

6) Check if there is paper jammed in the 
separation/feeder area. If there is, swing 
the feeder release lever counterclock- 
wise to open the feeder, then remove the 
jammed paper. Be careful not to tear it. 



When removing jammed paper from 
the separation area be very careful not to 

"►tou&theli'pii^eiserisitive drum. 




Figure 1-9 

7) Open the multifeeder cover, and remove 
the paper from the multifeeder tray. 

8) Hold the grip found at the bottom of the 
multifeeder cover, and open the right 
door; then, remove the jam. 




Figure 1-10 



Figure 1-8 



1 -10 



COPYRIGHT© 1992 CANON INC, 



CANON NP-1S50 REV.1 SEPT. 199! PRINTED IN JAPAN (IMPRIME AU JAP0N) 



I GENERAL DESCRIPTION I 



9) Close the right door. 




Figure 1-11 



1 0) Close the front door. 



B. ADD PAPER Indicator £ 

1. Cassette 

The indicator goes ON when no cassette 
is found in the cassette or no paper is found 
inside the cassette. 
1 ) Push the center of the cassette. 

• The cassette springs out automatically. 




Figure 1-12 



2) Set copy paper inside the cassette, 
r As many as 250 sheets of copy paper 
(80 g/rri) may be set. 




Figure 1-13 



3) Hold the center of the cassette, and slide 
it into the cassette holder until it stops. 

2. Multifeeder 

The indicator goes ON when the paper 
on the multifeeder tray is not positioned 
correctly or the multifeeder cover is left 
open. 

• As many as 50 sheets of copy paper 
(80 g/rri) may be set on the 
multifeeder tray. 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REM JAN. 1992 PRINTED IN JAPAN (IMPRIMEAUJAPON) 



1 -11 



■ GENERAL DESCRIPTION ■ 



C. ADD TONER 



Indicator i 



This indicator flashes when the amount of 
toner in the black developing assembly has 
become low. 
1. Black developing assembly 

1 ) Open the front door. 

2) Turn the developing assembly release 
lever counterclockwise. 

3) Pull the developing assembly forward as 
far as possible. 

4) Open the top cover of the developing 
assembly. 

5) Shake the toner cartridge back and forth 
about 1 times. 

6) Place the toner cartridge on the develop- 
ing assembly. 

7) While holding the toner cartridge in 
place, remove the seal slowly to allow 
the toner to flow out. 




Figure 1-14 



8) Tap the top of the toner cartridge to 
remove any toner remaining in the car- 
tridge. 

9) Carefully remove the toner cartridge. 

10) Close the top cover of the developing 
assembly. 

11) Put the developing assembly back into 
the copier. 

12) Swing the developing assembly release 
lever clockwise. 

1 3) Close the front door. 



2. CT Unit (color developing unit) 

If copy images become faint, the color 
toner has probably run out. In this case, 
replace the CT unit. The copy image can 
sometimes be temporarily restored by 
placing the CT unit in its storage box and 
agitating it. 



Note: 

The CT unit is a discardable type. 
When the color toner has been used up, 
toner is not added to the CT unit; rather, 
the entire unit is replaced. 



D. CONTROL CARD 
Indicators: 

The control card indicator operates on a 
copier with a control card unit. It flashes in 
the following cases. 

a) When there is no control card in the 
control card unit. 

b) When there is a control card in the 
control card unit but the indication on 
the control card unit is "P" or "EE". 



1 -12 



COPYRIGHT© 1992 CANONINC. 



CANON NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIME AU JAP0N) 



■ GENERAL DESCRIPTION! 



VI. DAILY INSPECTION 
TO BE PERFORMED 
BY THE CUSTOMER 

Carefully instruct the customer to be sure 
to clean the following parts of the copier 
once a week. 

1 . Primary corona assembly 

Slide in and out the wire cleaner to clean 
the corona wires. 

2. Copyboard glass 

Clean the copyboard glass with a damp 
cloth, then wipe it dry. 

3. Copyboard cover 

Clean the copyboard cover with a mild 
detergent solution, then wipe it dry. 

4. Transfer corona assembly 
Remove the transfer corona assembly 
from the copier, then slide the knob (wire 
cleaner) at the bottom of the transfer 
corona assembly back and forth to clean 
the corona wires. 

Further, clean the static eliminator using 
the cleaning brush (accessory). 



COPYRIGHT© 1992 CANON INC. CANON NP-1550 REV.1 SEPT.1992 PRINTED IN JAPAN (IHPRIHE AU JAPON) 1 -13 



I COPYING PROCESS I 



I. IMAGE FORMATION 
PROCESS 

A. Outline 

Copy board glass 

III II II " " rr\ 



/> i-JS — Scanning lamp 

<*r — <*> 

i 



Lens 



1 Developing T* 

Primary corona assembly assembly 



Pre-exposure lamp~-^^j\ 
Cleaning roller Drum cleaner.. 



assemrjiy i 




Lower fixing roller 



Figure 2-1 



This copier consists of the units shown in 
Figure 2-1. 

The image forming process is divided into 
the eight steps shown below. 
Step 1 : Pre-exposure 
Step 2: Primary corona (negative DC) 



Step 3: Image exposure 

Step 4: Developing (positive plus AC) 

Step 5: Transfer (negative DC) 

Step 6: Separation 

Step 7: Fixing 

Step 8: Drum cleaning 



Electrostatic latent image formation block 



c 



( 2. Primary corona ) ** ( 3. Image exposure j 



1 . Pre-exposure 



( 8 Drum cleaning ) 



J 



( Copy delivery j 



. Fixing ~~j 



6. Separatio 



( 4. Developing ) 

; J , , 

( 5. Transfer ) C Multi feed ") 
n j Q Registration ) 



c 



Cassette 



w 



COPYRIGHT© 1992 CANON INC. 



Flow of copy paper 
-»— Direction of rotation of drum 
Figure 2-2 

CANON NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON] 



2-1 



I COPYING PROCESS I 



The outer surface of the photosensitive 
drum is a layer of organic photoconductor 
(OPC).The base is an aluminum (conductive) 
cylinder. 



Photoconductive 
layer 

Base 




C. Step 1 Pre-Exposure 

r - " - !"^ Pre-exposure lamp 



Filter 




Figure 2-3 



Figure 2-5 



B. Electrostatic Latent Image 
Formation Block 

This stage consists of three steps. At the 
end of the stage, the drum has a pattern of 
negative electrical charges on its surface 
corresponding to the dark parts of the 
document image. The light areas of the 
document image are represented on the 
drum by an absence of charges. 

The pattern of negative charges cannot 
be seen by the eye, hence it is called an 
electrostatic latent image. 








Time (t) — 


/ 




r"\" 




/ 




i Light area 


-500- 


/ 




/ 
/ 




C 3 


ffl \ 
Q 
O 
O 






Dark area 


1000- 


^ Q. 


Ep 


Image exposure 




n. g> 


tk 


(step 3) 



Figure 2-4 



Before the primary corona step, light from 
the pre-exposure lamps is shone onto the 
surface of the drum (pre-exposure). This 
process ieliminates residual charges and 
helps to make the density of the copy even. 

D. Step 2 Primary Corona 



Primary corona assembly 




Figure 2-6 



The primary corona (negative) applies a 
uniform layer of negative charges over the 
drum surface. 

The drum surface potential, is determined 
by the grid potential. The grid is connected 
to ground through a varistor, which holds the 
drum potential constant at the varistor break- 
down voltage. 



2-2 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



E. Step 3 Scanning Exposure 



Optical image 




Light from the original is projected onto 
the drum surface. Charges in these light 
areas on the drum are neutralized by drum 
photosensitive effects. 

F. Step 4 Developing 



Blade 




Cylinder 

1 Developing 
Magnet j cylinder 



Figure 2-8 



I COPYING PROCESS ■ 



Color developer is a two-component type 
consisting of iron powder (carrier) and toner 
mixed together in a fixed ratio. The main 
component of the toner is resin. The toner is 
charged to a positive potential and the iron 
powder to a negative potential by friction with 
the rotating cylinder. 



— Blade 
/tk_ Concentrated 

Vay - magnetic 



Magnet 




Developer 



Figure 2-9 



A concentrated magnetic field develops 
between the magnet and the edge of the 
blade. This field attracts the charged 
developer. 

The developer is held virtually immobile by 
the magnetic field, forming a curtain along 
the edge of the blade. As the cylinder 
rotates, this curtain skims the toner particles 
on its surface to a thin uniform layer. 

An AC bias plus a negative DC bias are 
applied simultaneously to the developing 
cylinder so that the waveform of the 
developing bias has a larger negative 
excursion than positive. 



Positive 
excursion 

Negative 
excursion 



DC bias 



Figure 2-10 



As shown in Figure 2-8, the developing 
assembly consists of a developing cylinder (a 
stationary magnet surrounded by a rotating 
sleeve) and a blade made of magnetic 
material. Black toner is a single component 
type consisting of a fine powder of mixed 
magnetite and resin binder. The toner has 
insulating properties and is charged to a 
positive potential by friction with the rotating 
cylinder. 



During copying toner is attracted to the 
drum by the charges on the drum surface 
and by repulsion due to the developing bias 
(during the positive excursion), transforming 
the latent electrostatic image into a visible 
image. Excess toner particles are attracted 
back to the cylinder from the drum due to the 
charges on the drum surface and the 
developing bias (during the negative 
excursion). 

The DC bias affects copy density and 
fogging: As the DC bias becomes less 
negative (approaches 0V), the density and 
degree of fogging both increase. 



COPYRIGHT© 19)2 CANON INC. 



CANON NW550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIHE AU JAPON) 



2-3 



I COPYING PROCESS I 



G. Step 5 Transfer 



H. Step 6 Separation 



Copy paper 




Copy paper 



Transfer corona 
assembly 




Figure 2-11 



Figure 2-12 



In this step, a negative corona is applied 
to the back of the copy paper, attracting the 
toner from the surface of the drum to the 
copy paper. 



The copy paper is separated from the 
drum by utilizing its stiffness. Thin paper, 
however; is not stiff, and may wrap around 
the drum instead of separating from it. To 
prevent this, a positive voltage is applied to 
the separation static charge eliminator, 
weakening the attraction between the drum 
and the copy paper. This enables the paper 
to separate easily from the drum. 



2-4 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPfllME All JAPON; 



I COPYING PROCESS I 



I. Step 7 Fixing 



Cleaning roller 

Upper fixing roller 



Tungsten-halogen 
heater (900W) 



Lower fixing roller 




Toner 



Copy paper 

Figure 2-13 



In this step, the copy paper is pressed 
between two heated rollers to make the toner 
image permanent. 

To prevent the copy paper from wrapping 
around the roller and toner offsetting 
(adhesion of toner to the roller and transfer of 
the toner to the next copy), the surface of the 
upper fixing roller is cleaned with the cleaning 
roller. 



II. AUXILIARY 
PROCESSES 

A. Blank Exposure 

Blank exposure is the process of shining 
light onto is simply the removal of the drum 
surface potential in the non-image areas 
resulting from REDUCTION copying and 
using some cassette sizes (paper sizes). The 
light for this is produced by the precondition- 
ing lamp and is reflected onto the drum by a 
reflector. 

In the non-image area on the drum 
between successive sheets of copy paper, 
the grid bias of the primary corona is reduced 
to prevent adhesion of toner. For these; 
areas, there is no blank exposure for removal 
of the surface charges. 

B. Ozone Filter 

A catalytic ozone filter in the exhaust fan 
prevents ozone (generated by the coronas) 
from escaping to the atmosphere by con- 
verting the ozone to oxygen. 



J. Step 8 Drum Cleaning 



Cleaning blade 




Paddle 



Toner catcher 



Figure 2-14 



This step prepares the drum surface for 
the next copying operation. Any residual 
toner scraped off the drum by the cleaning 
blade and picked up by the toner catcher. It 
is then pushed to the back by the paddle. 



COPYRIGHT© 1992 CANON INC 



CANON NP-1 550 REV.O JAN. 1992 PRINTED IN JAPAN (IMPRIMEAUJAPON) 



2-5 



■ OPERATIONS AND TIMING ■ 



I. BASIC OPERATION 
A. Functions 

The copier can be divided into four functional sections: paper pick-up and feed system, 
exposure system, image formation system, and control system. 




Figure 3-1 



COPYRIGHT © 1992 CANON INC. 



CANON NP-1550 HEV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



3-1 



■ OPERATIONS AND TIMING ■ 



B. Outline of Electric Circuitry 

The NP-1550's main mechanisms are 
controlled by the microprocessor, PROM, 
and EEPROM on the DC controller PCB. 

1. Microprocessor (Q303) 

• controls the copying sequence 

• controls the control panel 

• controls the main motor/scanner motor 

• controls the scanning lamp 

• reads the analog signals 

2. PROM (Q318) 

• contains the sequence program 

3. EEPROM (Q315) 

stores data that can be modified in the 
service mode (replaces conventional 
variable resistors and switches) 

- | *>*!;.....„i.v,.T n .,.,,..- „,..„„,, ., r .,.,~ .,, 

^EHPRGM'k a type oT,rtQfvt:,W..w.hfcft" 
. ■ datajrnay;tie Erased or st^ftrfiply/. , , . ' ' 
For this reason, the NP-1550's RAM 
and RAM are not backed up by a lithium 
battery. 



.W^™,,,,^:,,,^.^, ,.,./ ,,, ,„, - . 

The NP-1550 is equipped with an A/D 
converter and, therefore, its micro- 
processor can read analog signals. 



Note: 

The main motor (M1) is a synchronous 
motor that uses the frequency of the 
power supply as the reference of its 
operation. 

The scanner motor (M2) are stepping 
motor that use the oscillation frequency 
of the crystal oscillator on the DC con 
trailer. 

Fluctuations of the frequency in the 

power supply during copying operation 

^affects only the revolution of the main 

motor (M1) and result in :expahsjdn; s Or 

contraction of the images. V ! ■ ? 



3-2 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REM JAN.1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



I OPERATIONS AND TIMING! 



(Sensor) 



Scanner home position sensor 
Lens home position sensor 
Cassette paper sensor 
Delivery paper sensor 
Pre- registration paper sensor 
Multifeeder paper sensor 



Cassette size sensor 
Right door switch 



Black toner level sensor 



Control panel 



(Control panel) 
DC controller PCB 



Microprocessor (Q303) 



Sensors, Switches 



^ PROM 
(Q318) 



EEPROM 
(Q315) 



v^ 



Driver 
(Q308) 





Loads 


, 


AC driver/DC 
power supply PCB 


» 


Main motor 








Fixing roller heater 





MuKifeeder clutch 
Registration roller clutch 
Lens solenoid 
Pick-up clutch solenoid 
Blank solenoid 
Multifeeder solenoid 



Primary/Transfer 
corona assembly 

Developing bias 

Grid bias 



Lamp regulator 




Scanning lamp 





*■ Scanner motor 



Pre-exposure lamp 



Exhaust fan 
Scanner cooling fan 
Feeder tan 



Sensors, Switches 



-| Microprocessor | 




Sorter 


Sorter controller PCB 


- * 







-j Microprocessor | 




ADF 


ADF controller PCB 


* * 







Figure 3-2 



COPYRIGHT© 1992 CANON IMC. 



CANON NP-1550 REV.O JAN. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



3-3 



■ OPERATIONS and timing ■ 



C. Inputs to DC Controller 

1. Inputs to DC Controller (1/2) 



DC controller PCB 



Multifeeder paper sensor 



3 



02 J23-1 



Pre -registration paper 
sensor 



Scanner home position 
sensor 



3 



35 



Lens home position sensor 



Delivery paper sensor 



Cassette paper sensor 



3 



^B 



It 

5V 



7hr 

5V 






5V 



5V 
CPEP 



when paper is over Q1 , "1 '. 
(light-blocking plate is at Q1 ) 



when paper is at Q2, '1'. 
(light-blocking plate is at Q2) 



when scanner is at home position, '1'. 
(light-blocking plate is at Q3) 



when lens is at home position, '1'. 
(light-blocking plate is at Q4) 



when paper is at Q5, '0'. 
(light-blocking plate is not at Q5) 



when paper is in cassette, '1'. 
(light-blocking plate is at Q11) 



Figure 3-3 



3-4 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.0 JAN.1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



I OPERATIONS AND TIMING I 



2. Inputs to DC Controller (2/2) 



DC controller PCB 



AE 



AE sensor 



24V 



Black toner 
level sensor 



HOh 

' : 


c 



TH1(NTC1) 



CST(SW3) 



Cassette size 
sensor 



Right door 
switch 



[1 



Control panel 



AE 
AEGIN 



1W 



5V 



BTEP 
CTD 



TH1 
"^7 



9p.3-25 



when black toner in black developing 
assembly is below specific level, '0'. 

when color developing assembly is set, '1'. 



The voltage lowers as the fixing heater 
temperature rises. 



CSZ1 
CSZ2 
CSZ3 
CSZ4 

oscillation signal 



Reads the cassette size; see p.3-32 



RDC 



when right door is closed, '0'. 



Figure 3-4 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIMEAUJAPON) 



3-5 



■ OPERATIONS AND TIMING I 



D. DC Controller Outputs 
1. DC Controller Out Puts (1/3) 



DSW SW1 

<r~o <y^~ 



DC controller PCB 



e 



<n> 



J101 -1 

r 



Main motor 







J104 -1 



Fixing roller heater J4 J106 
-" -3 



r-^TTTinr^-o- 



H1 -2 _! 
-o~"o o L 



TS1(F1) 
Thermo-switoh J1 07 " 2 




S 



lr 



^n t 24V 



S105 AC driver _ 



J601 -1 



Scanning lamp 



^ 



| LA1 



3 — ^v 



J602 ilLamp regulator| 



FU2. -3 1 



Scanner motor ( M2 



J105 J306i 
-3 -3 



MMD when "1" -. main motor ON 



-4 -2' 



HTRD When T->fixing roller 
heater ON 



-2 -4 



J603 J305 



I 
-1 -61 



ACOFF When "0" — AC driver OFF 
24V 



-4 -3 



-5 -2 



-3 -4 



-2 -5 



LAON 

LIC 

LIGHT 



See page 3-20 



c> 



1r 



See page 3-16 



Figure 3-5 



3-6 



COPYRIGHT© t992 CANON INC. 



CANON NP-1SS0 REM SEPT. 1992 PRINTED IN JAPAN (IMPfHHE AU JAPON) 



I OPERATIONS AND TIMING ■ 



2. DC Controller Out Puts (2/3) 



Pick-up clutch solenoid 



SL1 



Lens solenoid 



SL2 



Multifeeder solenoid 



SL3 



Blank solenoid 



SL4 



Registration roller clutch 
CL1 




Multifeeder clutch 




DC controller PCB 



J308-5 



J 304-1 



J312-11 



J308-7 



J308-3 



J312-9 



24V 



PUSD when '0', SL1 ON. 



24V 
J 



LNSD when '0', SL 2 ON. 



24V 
J 



MFSD when '0', SL3 ON. 



24V 



BLSD when '0', SL4 ON. 



24V 



RGCD when '0', CL1 ON. 



24V 
J 



MFCD when '0', CL2 ON. 



Figure 3-6 



COPYRIGHT© 1992 CANONINC. CANON NP-1SS0 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIHE AU JAPON) 



3-7 



■ OPERATIONS AND TIMING ■ 



3. DC Controller Out Puts (3/3) 



DC controller PCB 



J309-1 



Scanner cooling fan ( FM1 



Exhaust fan 



24V 



Feeder fan 



/^-y 




J311-1 


r 


( FM2J 


-3 




^ r- 




J313-6 


FM2D 


(FM3 j 




r 


-7 




FM3D 




J731 J308 


Pre-expos 


ure lamps 





FM1D When "0" — FM1 ON 



24V 



FM2D When "0" - FM2 ON 



24V 



FM3D When "0" - FM3 ON 



— ^ WV 1 

— ^ <WV 



-2 -1 1 j 24V 



-1 -2 



Total counter 



CNT1 



J313-2 



-1 



PEXP When "0" - Pre-exposure lamps ON 



24V 



TCNTD When "0" - Total counter operates 
(only for 1 00V copier when making 
1 black and white copy) 



Control card unit 



C.C.V. 

(CC1) 



J315-4 



J314-13 



J314-14 



J315-3 



H V T 



c 



5V 



CCNTD When "0" -> operates 



CCNNT When "0" - card sensed 



^T 



See page 3-21 



Figure 3-7 



3-8 



COPYRIGHT© 1992 CANONINC. 



CANON NP-1550 P.EV.1 SEPT. 1 992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



■ OPERATIONS AND TIMING I 



E. Basic Sequence of Operations (Direct, Continuous Copying 
(2 sheets)) 



WMUPR 
POWER SWITCH 170°C 180°C COPY START key 

ON (150°C) (160°C) ON SCRV 
\7 V X7 V \ 


SCRV 
\ 








WMUP 




STBY 


INTR 


SCFW 




SCFW 




LSTR 


STBY ^ 










AER 




















(, 
























t. 


Primary / transfer 






















t, 








Scanner is set for 
HOME position 




Forward 


Reverse 














■ m 








mm 







* Numbers in parentheses apply to 
when the CT unit is used. 



Figure 3-8 



Period 


Purpose 


Remarks 


WMUP 


From switch on until the 


Allows time for fixing 


Warm-up time varies 


(Warm-Up) 


fixing roller temperature 


roller to warm up 


with fixing roller 




reaches 1 70°C for the 




temperature at power 




black developer or 




ON. When the COPY 




150°C for the CT unit. 




START key is lighting 




(About 75 seconds at an 




green. 




ambient temperature of 








20°C) 






WMUPR 


Until the fixing roller 


Keeps fixing roller tem- 


• After the WMUPR pe- 


(Warm-Up 


temperature reaches 


perature uniform 


riod ends, the 


rotation) 


170°to180°Cforthe 




READY/WAIT indica- 




black developer or 1 50° 




tor changes from 




to160°CfortheCT 




orange to green. 




unit 




• Even when the fixing 
roller has warmed 
up, it rotates for at 
least 4.2 seconds. 


INTR 


About 2.2seconds after 


Stabilizes drum sen- 


A PAPER FEED signal is 


(INITIAL 


COPY START key is 


sitivity to prepare for 


generated to feed first 


rotation) 


pressed 


copying 


sheet of copy paper. 

Note: 

AE mode: About 3.2 

seconds 
Non-AE mode: About 2.2 
seconds 



Table 3-1 (a) 



COPYRIGHT© 1992 CANONINC. 



CANON NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIME AU JAP0N) 



3-9 



■ OPERATIONS AND TIMING ■ 



Period 


Purpose 


Remarks 


AER 

(AE rotation) 


From when the scanner 
moves forward about 70 
mm from the end of the 
image until it returns to 
its home position. 


Move the scanner for- 
ward about 70 mm from 
the end of the image 
and measure the docu- 
ment density. 


In the non-AE mode, the 
scanner does not move 
forward or in reverse. 


SCFW 

(Scanner 

Forward) 


When the scanner is 
moving forward 
• Travel distance 

changes with copy 

paper size. 


Scanning lamp illumi- 
nates original, and ref- 
lected optical image is 
transmitted to photo- 
sensitive drum through 
mirrors and lens array. 


•A REGISTRATION sig- 
nal is generated, and 
copy paper is fed to 
transfer area. 

• A PAPER FEED signal 
is generated to feed 
next sheet of copy 
paper. 


SCRV 

(Scanner 

reverse) 


While the scanner is 
moving in reverse 
• The speed of the re- 
verse movement is 
2.5 times that of the 
forward movement. 


Scanner is moved back 
to HOME position to pre- 
pare for next copy 




LSTR 

(LAST rotation) 


Untill the main motor 
stop after SCRV for last 
copy ends 


Ensures full ejection of 
last copy 




STBY 
(STANDBY) 




Waits until COPY;START 
key is pressed 





Table 3-1 (b) 



3-10 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.O JAN.1992 PRINTED IN JAPAN (IMPRIMEAUJAPON) 



■ OPERATIONS AND TIMING ■ 



II. EXPOSURE SYSTEM 

A. Changing the 
Reproduction Ratio 

The reproduction ratio across the drum is 
varied by changing the position of the lens. It 
is moved by the lens drive system. The 
reproduction ratio around the drum is varied 
by changing the speed of the scanner. 
Figure 3-9 shows how the position of the lens 
is varied to change the reproduction ratio 
across the drum. 



DIRECT 



REDUCTION £ 



ENLARGEMENT ( 




Figure 3-9 



B. Lens Drive System 

1. Outline 

The lens is moved by the scanner motor 
(M2). Normally, the coupling gear is in its 
upper position, and connects the scanner 
motor to the scanner drive capstan. To move 
the lens, the lens solenoid (SL2) goes ON, 
causing the coupling gear to disengage from 
the scanner capstan gear and engage with 
the lens capstan gear. The lens is a "floating 
element" type. In operation, the relative 
position of lens elements (individual lenses) 
changes, and the focal length changes as a 
result, but the changes are to optimize lens 
sharpness for each reproduction ratio, not to 
make the lens function as a zoom lens. (The 
lens should not be dismantled.) 

When the scanner motor rotates (CW), 
the lens will be moved to the left (for 
ENLARGEMENT) by the capstan and cable. 

When the cassette size is changed or 
when the copier is in the REDUCE mode, the 
blank exposure shutter moves in relation to 
the distance over which the lens travels, 
thereby blanking out the width corresponding 
to the reproduction ratio; see p. 3-28. 

The DC controller indicates 'E210' on the 
control panel in response to an error in the 
lens drive system. 



The scanner drive system changes the 
reproduction ratio around the drum by 
varying the speed at which mirror 1 moves 
relative to the peripheral speed of the drum. 
(The scanner is mirror 1 plus the scanning 
lamp.) 

The mirror speed is faster than the drum 
peripheral speed for REDUCTION and 
slower for ENLARGEMENT 

Note; r :.,., 
;M« The relative ; position of the mirrors is 

not Changed to vary the reproduction 

ratio. 
S; 2l For DIRECT copying, the speed of the 

mirror is the same as the peripheral 

speed of the drum. 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.O JAN. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



3-11 



I OPERATIONS AND TIMING! 



Coupling gear 



Scanner drive capstan 




Figure 3-10 



3-12 



COPYRIGHT© 1 992 CANON INC. 



CANON NP-1550 REM JAN. 1992 PRINTED IN JAPAN {IMPRIME AU JAPON) 



■ OPERATIONS AND TIMING I 



2. Basic lens Drive System Operation 
(change of reproduction ratio) 



POWER SWITCH , COPY START key 
ON ON 

y ■■ „ v 












WMUP. 


INTR 


SCFWl, 






AER 






Scanner home 
position (Q3) signal 








© © /Reverse 








Scanner movement 


Forward 








Lens solenoid 
(SL2) 












® © © 








Movement of lens 


^ta VU////A ^H V//SMK 








Lens home position 
(Q4) signal 










■ I II U"'~ 






\ 




Figure 3-11 


©CCW rotation 
©CW rotation 


©ENLARGEMENT 

direction 
©REDUCTION 

direction 
© Blanking by 

CASSETTE SIZE 



When the casette size is changed or: 
when the copier is in the ZOOM mode, the 
lens first returns to the home position before 
moving to the position that corresponds to 



the cassette size and the reproduction ratio. 
This operation is executed also when the 
ZOOM mode is switched to the DIRECT 
mode. 



COPYRIGHT© 199! CANONINC. 



CANON NP-15S0 REV.1 SEPT. 1992 PRINTED IN JAPAN (IHPRIHE AU JAP0N) 



3-13 



■ OPERATIONS AND TIMING ■ 



C. Scanner Drive System 

1. Outline 

The scanner is driven by the scanner 
motor (M2). The direction of rotation of the 
scanner motor determines whether the 
scanner moves forward or backward. The 
forward speed of the scanner motor is 
continuously variable to produce the 
required reproduction ratio. The reverse 

Mirror 2 mount 



Mirror 1 mount 



speed is fixed regardless of the reproduction 
ratio (2.5 times the forward speed for 
DIRECT copying). 

The distance that the scanner moves 
varies to suit the size of copy paper and the 
reproduction ratio. 

The control panel displays 'E202' in 
response to an error in the scanner motor 
(M2) or the scanner home position sensor 
{03). 



Scanner home position 
sensor (Q3) 




Figure 3-12 



3-14 



COPYRIGHT© 1992 CANON INC. 



CANON, NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIMEAUJAPON) 



I OPERATIONS AND TIMING! 



2. Relation Between Scanner Sensor 
and Signals 



Scanner 
sensor 


Signal 
name 


i Scanner 


Meaning 


Forward 


Reverse 


Scanner home 

position sensor 

(03) 


SCHP 


~t_ 




• Grid bias ON 




a 


• After 0.1 seconds, scanner stops 
advancing 



3. Basic Scanner Operation 



Table 3-2 



POWER switch ON. COPY START key ON 
V , V 



Scanner home 
position sensor 
(Q3) signal 



Pre-registration paper 
sensor (Q2) signal 

Scanner movement 



Scanning lamp 



WMUP 



STBY 



INTR 



AER 



SCFW 



Forward 



SCRV 



SCFW 



SCRV 



■////////. 



LSTR (, 



Figure 3-13 



COPYRIGHT© 199(2 CANON INC. 



CANON NP-15S0 REV.1 SEPT. 1992 PRINTED IN JAPAN (IHPRIHE AU JAPON) 



3-15 



■ OPERATIONS and TIMING I 



4. Scanner Motor Drive System 
Operation 

a. Clockwise rotation 

The scanner motor driver outputs pulses, 
and the motor rotates CW. This moves the 
lens in the direction for REDUCTION, and 
the scanner moves forward. 

For REDUCTION copying, the motor 
speed increases to move the scanner faster 
(forward). 



b. Counterclockwise rotation 

The scanner motor is driven CCW by 
pulses of phase relationship opposite to that 
used to drive it CW. This moves the lens in 
the direction for ENLARGEMENT, and 
moves the scanner in reverse. 



DC controller PCB 

36V Motor power supply 



J302-5 



COMA 



{jM^jj 



Scanner motor 
(M2) 




Output shaft 



T COMB -jt_ 



J302-2 




Figure 3-14 



3-16 



COPYRIGHT © 1992 CANON INC. 



CANON NP-1550 REM JAN.1992 PRINTED IN JAPAN (IMPRIMEAUJAPON] 



I OPERATIONS AND TIMING ■ 



5. Scanner Movement for Two-page 
Separation Mode (copy count "2") 



Doc. L.E. Doc. LE. Doc. LE. Doc. L.E. Doc. LE. Doc. L.E. 
(1st page) (1st page) (1 st page) (2st page) (1st page) (2st page) 

INTR — l. SCRVI, SCRVI i i SCRV2 i l SCRV2 






SCFW1 




SCFW1 




SCFW2 


\ 


SCFW2 


V 


LSTR 


Scanner home position 
sensor signal (Q3) 


— 1 — 




-I- 




— I— I— W— 




— n — j— m— 






■ 


i 


I 


!■ 


■ ■ 




SCANNER FORWARD 
command (SCFW) 


















SCANNER REVERSE 
command (SCRV) 






































Scanning lamp 






















-- Forward -« 






















orwar 




V1.7X 











r-^STBY 



Reverse Reverse 

Figure 3-15 



Timing of operations I, II, and III shown in 
figure 3-15 is with reference to the leading 
edge of the first page of the document (fall of 
Q3 signal). 

I : The distance traveled by the scanner from 
the leading edge of the original is 
determined by the reproduction ratio and 
the copy paper size, just as for a normal 
copy. 

II: This is roughly the same as I. If the 



forward distance traveled by the scanner 
is greater than 21 mm (220V, or 240V 
copier) the DC controller will judge that 
210 mm is the leading edge of the 
original. If the distance that the scanner 
moves forward is less than 21 mm, the 
point at which the scanner reverses in I 
will be the leading edge of the second 
page of the document. 
l:Same as I. 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IUPRIMEAUJAPON) 



3-17 



I OPERATIONS AND TIMING I 



III. IMAGE FORMATION 
SYSTEM 

A. Outline 

The basic structure of the image forma- 
tion system is as shown below. 



Scanning lamp control system 

Primary/transfer corona current and grid 

bias voltage control system 

Controlling developing bias 

Document density measurement system 

Developing assembly/Drum cleaner 

Blanking 




When shorted, 
signal sent to 
indicate black 
developing 
assembly. 



Figure 3-16 



3-18 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



I OPERATIONS AND TIMING I 



B. Basic Operation of Image Formation System 
(black developing assembly, 2 copies) 





COPY START 
WMUPR 9-7 


key 
















WMUP 


V 


STBY 


INTR 


SCFW 


SCRV 


SCFW 


SCRV 


LSTR 


STBY <> 










AER 
















Main motor (M1) / 
pre-exposure lamp 






Scanner movement 












Forward 


Backv 


»ard 








Scanner home position 
sensor (Q3) siqnal 






















Scanning lamp (LA1) 
























Primary / transfer 
corona assembly 
























Grid bias ON /OFF 


































^^^^^^^^M 




^^^^^^^^M 






<- 


Developing bias DC 
component 
























Developing bias AC 
component 
























Light intensity 

CONTROL command 






















^ 



When CT unit is used. 



Figure 3-17 



When a color developing (CT) unit is used, the AC component of the bias operates when the 
main motor (M1) is operating. 



COPYRIGHT© 1992 CANONINC. 



CANON NP-1550 REM SEPT. 1992 PRINTED IN JAPAN (IMPRIMEAUJAPON) 



3-19 



■OPERATIONS AND TIMING I 



C. Controlling the Scanning 
Lamp 

1. Outline 

The scanning lamp (LA1) is controlled by 
the DC controller PCB; see Figure 3-18. 
Specifically, the DC controller 

• turns the scanning lamp ON and OFF. 

• controls the intensity of the scanning 
lamp. 

2. Mechanism 

a. Turning the Scanning Lamp ON and OFF 

The microprocessor (Q303) on the DC 
controller PCB controls the lamp regula- 
tor. The scanning lamp goes ON when 
the scanning LAMP ON command (LAON) 
is '1', and it goes OFF when the signal is 
'0'. 

b. Controlling the Intensity of the Scanning 
Lamp 

The intensity of the scanning lamp is 
switched between when the black devel- 
oping assembly is used and when the CT 



unit is used. 

When the CT unit is used, the LIGHT 
INTENSITY CONTROL command (LIC) 
goes '0' to raise the lamp voltage by 
about 3.5 V higher than when the black 
developing assembly is used. 

During AE exposure, however, the 
voltage (70 V) applied to the scanning 
lamp remains the same. 

The NP-1550 adjusts the copy density 
using its development bias; see p. 3-22. 
Error Protection 

The> condition of the scanning lamp is 
monitored using the LIGHT signal 
(LGHT). 

If the LIGHT signal (LIGHT) is received 
by the DC controller for about 20 sec, the 
error detection circ uit gene rates the AC 
SHUTOFF signal (ACOFF) to force the 
relay (S105) on the AC driver/DC power 
supply, PCB to go OFF, thereby cutting 
AC power supply (P. 3-39). In this case 
E220 error is displayed. 




DC controller PCB 



Lamp regulator 
Figure 3-18 



3-20 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIKE AU JAP0N) 



I OPERATIONS AND TIMING! 



D. Primary/Transfer Corona 
Current and Grid Bias 
Voltage Control System 

1. Outline 

The circuit shown in Figure 3-17 conntrols 
the primary/transfer coronal current and the 
bias voltage of the grid. of the primary 
corona. Main functions are as follows. 

a. Switching primary/transfer corona current 
ON/OFF 

b. Maintaining primary/transfer corona cur- 
rent constant 

c. Switching primary corona grid bias volt- 
age 

d. Switching primary corona grid bias 
ON/OFF 

In order to eliminate the effect of changes 
in atmospheric conditions on the effective- 
ness of the corona discharge, the current to 
the primary corona wire is maintained 
constant. 

The primary corona and transfer corona 
current are switch ed ON a nd OFF by the 
HVT ON command (HVTON). 

The grid bias voltage is switched by the 
GRID ON signal (GRDON). 



2. Switching Primary/Transfer Corona 
Current ON/OFF 



When HVTON = 1 
(-.Differential amplifier goes OFF. 
I— Variable pulse width oscillator goes OFF. 
I — ►High-voltage transformer goes OFF. 
When HVTON = 
I, 



Differential amplifier goes ON. 

riabie pulse width oscillator goes Ol 
■ High-voltage transformer goes ON 



3. Maintaining Primary/Transfer 
Corona Current Constant 

If the primary corona current is greater 
than the correct value due to changes in the 
environment, the level (analog) of the 
feedback signal to the differential amplifier 
circuit will increase and the output from the 
differential amplifier circuit will fall. As a 
result, the primary/transfer coronal current 
will fall. Similarly, if the primary corona 
current is too low, it will be increased. 

If the output side of the high-voltage 
transformer supplying the primary corona 
assembly should be overloaded, the current 
will be limited to a certain maximum. 



DC controller PCB 



High-voltage transformer (HVT) 



Primary corona 
assembly 

I Photosensitive 1 




Transfer corona 
assembly 



Figure 3-19 



COPYRIGHT© 1992 CANON DC. 



CANON NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



3-21 



■operations and timing ■ 



4. Controlling Grid Bias Voltage 

a. During s canning, the DC controller PCB 
outputs GRDON = "0". 

I»Q7 goes ON and the comparator 
output is "L". 

L Q6 goes OFF. 

L> Current does not flow into trans- 
former T4 and Q5 goes ON. 

'-►Bias is applied to the grid. 

L*The surface of the drum is 
charged. 

The voltage applied to the grid is fed back 
to the comparator which functions to 
maintain the grid voltage constant. 

b. When scanning is not taking place, t he 
DC controller PCB outputs GRDON = 
"1 ". 

Lqj goes OFF and comparator circuit 
output is "H". 

■-►Q6 goes ON and current flows into 
T4. 

I— Bias is not applied to the grid. 

Under the above conditions, the surface 
of the drum is not charged, hence toner does 
not adhere to it (blanking). 

The timing at which the grid bias is 
switched may be varied using Z3' or T6' in 
the service mode (leading edge non-image 
width adjustment). 



E. Controlling Developing 
Bias 

1. Outline 

The circuit shown in Figure 3-18 controls the 
developing bias. Its main functions are as 
follows. 

a. Switching AC component of the developing 
bias ON/OFF. 

b. Regulating voltage of the DC component 
of the 'developing bias. 

The copy density can be controlled by 
varying the voltage of the developing bias to 
suit the following variables. 

a. Settings of COPY DENSITY lever and 
recalibration dial 

b. AE sensor output 

c. Type of developing assembly 

When there is a black developing assem- 
bly in the copier, J303-1 and J303-4 are con- 
nected electrically to inform the copier that a 
black developing assembly is in place. 

The photosensitive drum gradually 
deteriorates with use, causing the potential 
(Vl) of light areas of the drum tp increase, so 
that copy density is not correct for a given 
setting of the copy density lever. To 
compensate for this, a COPY DENSITY 
knob, which can be turned to raise the DC 
bias by exactly the increase in Vl, and thus 
produce clear copies again. 

2. Operation 

a. Switching AC component of the 
developing bias ON/OFF 

The square wave generator operates 
continuously when the copier is switched 
ON. 



a) WhenACBON = 1 

LaC bias switch circuit goes ON. 

L Output from the square wave gener- 
ator is cut off. 

So AC bias is not supplied to the devel- 
oping cylinder. 



3-22 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIMEAUJAPON) 



■ OPERATIONS AND TIMING ■ 



b) When ACBON = 

'♦•The AC bias switch circuit goes OFF. 

So the output of the square wave 
oscillator goes to the T1 drive circuit. This 
causes the AC high-voltage transformer to 
generate a 1300VAC AC bias, which is 
supplied to the developing cylinder. 

Also, the output of the AC high-voltage 
transformer is rectified and suppled to the 
static charge eliminator (apprbx. 3.2 kV). 
b. Controlling DC bias 

The differential amplifier of Figure 3-21 
operates when DCBC is 16V or below. (The 
range of DCBC (analog) is 6 to 16V, as set 
by the copy density cursor or the AE 
system.) 

I — >■ Differential amplifier goes ON. 

I-* Variable pulse-width oscillator goes 
ON. 

L-»DC high-voltage transformer goes 
ON. 

The DC bias is applied to the developing 
cylinder. 



The copy density knob changes the DC 
component of the developing bias as shown 
in Figure 3-20. 

COPY DENSITY lever scale 
« , , , (?) , , . P 



-100 
-200 
-300 
-400 
-500 




DC bias 

Figure 3-20 Changes in Development 
Bias (DC component) by 
COPY DENSITY knob 



DCBC 


6Vto16V 


DC component of 
developing bias 


-500V to -0V 



DC controller PCB 



High'- voltage transformer unit (HVT) 




Figure 3-21 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1S50 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIME AU JAP0N) 



3-23 



■ OPERATIONS AND TIMING I 



3. Developing Bias Operation 





COPY START key 
WMUPR ON 

\ V 


SCRV 

\ 


SCRV 

\ 








WMUP 


\ 


STBY 


INTR 


SCFW 


\ 


SCFW 




-STR 


STBYt, 










AER 
















Main motor (M1 ) 




i. 


Scanner home position 
sensor (Q3) signal 






















AC BIAS ON command 
(ACBON) 
























DC BIAS CONTROL 




.. 




* * 




* 


* * 


* . 




** 




command (DCBC) 




W//// 




'///////// 




«.'/// 




■////M'/SSM 


) \ 



Figure 3-22 



The value of the DC BIAS CONTROL 
command and the DC bias are deter- 
mined by (1) the setting of the COPY 
DENSITY lever and COPY DENSITY 
knob, (2) the AE sensor output, and (3) 
the type of developing assembly installed. 
The DC bias used at times other than 
during scanning depends on the type of 
developing assembly installed. 
Black developing assembly: Approx. 
-320V CT unit: Approx. -220V 



Note; 

The AC component is added to the 
developing bias for a CT unit when the 
main motor is operating. 



3-24 



COPYRIGHT© 199! CANON INC. 



CANON NP-15S0 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



I OPERATIONS AND TIMING! 



F. Document Density 
Measurement System 

1. Outline 

There is an automatic density adjustment 
(AE) system which adjusts the DC 
component of the developing bias to suit the 
density of the original. If the density of the 
original is more or less uniform, the AE 
function varies the DC component of the 
developing bias to suit the density of the 
original, so that copies of the correct density 
will be made. 

2. Operation 

The scanner moves forward approxi- 
mately 70mm past the leading edge of the 
original and stops momentarily. The 
scanning lamp goes ON for approximately 
one second, the image density is read by the 
AE sensor, and the sensor output is 
interpreted by the DC controller. The DC 
controller then adjusts the DC component of 
the developing bias accordingly. 




3. Reading the Output of the AE 
Sensor 

The AE sensor consists of a photodiode 
(Q702) and an operational amplifier (Q701). 
If the strength of light striking the photodiode 
is high, the output voltage (AE) of the 
amplifier will be small. If the amount of light 
is small, the output voltage will be large. 

The DC controller reads the output at a 
certain time after the zero-cross signal 
(ZXDP) is received from the DC power 
supply. 

The data representing the adjusted AE 
reference/slope values are written to 
EEPROM when 'CD' or 'CI' is used in the 
service mode. 



For reference: B6size 



Approx. A is the position of the AE sensor 

A PP rox - 25mm 
25mm 

Figure 3-23 




AE sensor PCB 



DC controller PCB 



COPYRIGHT© 1992 CANON INC. 



Figure 3-24 

CANON NP-15S0 REV.0 JAN. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON] 



3-25 



■ OPERATIONS and timing I 



4. Adjustment 

Make the following adjustments when the 
AE sensor or the DC controller PCB has 
been replaced. 

1) Remove the potentiometer cover at the 
back of the left cover. 

2) Set the power switch ON. 

• Wait until the WAIT period has ended. 

3) Place an NB-3 or NA-2 test sheet on the 
copyboard, and lower the copyboard 
cover. 

4) Press switch SW 300 on the DC control- 
ler PCB. 

• "0" will appear on the COPY COUNT/ 
RATIO indicator on the control panel. 

• If "0" does not appear, press the "0" 
number key on the control panel so that 
"0" appears. 

5) Press the SORT/GROUP key on the 
control panel. 

• The scanner will move forward to the 
AE measuring position, then the scanning 
lamp will go ON. (Note) 

6) Adjust VR 301 on the DC controller so 
that "22" appears on the COPY COUNT/ 
RATIO indicator. 



10) Make a note of the numerical value 
displayed on the COPY COUNT/RATIO 
indicator. 

1 1 ) Press the SORT/GROUP key. 

• "0" will appear on the COPY COUNT/ 
RATIO indicator. 

1 2) Press the "1 " number key. 

• "1i" will appear on the COPY COUNT/ 
RATIO indicator. 

13) Enter the value recorded in step 10) 
using the NUMERIC keypad. 



in- 




■ Document density 



jTest sheet Sheet of newspaper 

<=£: when the setting is lowered. 
•+ : when the setting is raised. 

Figure 3-26 




Test sheet Sheet of newspaper 

Figure 3-25 



Document density 



7) Press the SORT/GROUP key. 

• The scanning lamp will go OFF, and the 
scanner will return to the HOME position. 

8) Remove the test sheet, place a sheet of 
newspaper on the copyboard, and lower 
the copyboard cover. 

9) Press the SORT/GROUP key. 

• The copier will perform the same 
operations as described in step 5). 



3-26 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1S50 REV.f SEPT. 1992 PRINTED IN JAPAN (IMPRIME AU JAP0N) 



■ OPERATIONS AND TIMING I 



G. Developing Assembly/ 
Drum Cleaner 

1. Outlines 

The paddle inside the drum cleaning unit 
and also the developing cylinder are rotated 
by the main motor. 

The amount of toner in the developing 
assembly is sensed by the black toner level 
sensor (TS1). 

When the amount of toner falls below the 
required quantity, the ADD TONER indicator 
on the control panel will flash. 

When the toner in the CT unit is used up, 
the entire CT unit should be replaced. 

The toner collected by the cleaning blade 
is stored in the drum cleaning unit: 

The developing assembly is pressed 
against the drum by a bam that presses 
against the developing assembly rail. (The 
cam is operated by the developing assembly 
release lever.) 

2. Remaining Toner Sensor 

The black developing assembly has a 
piezoelectric type sensor (TS1) which 
senses if the toner remaining in the hopper 
of the developing assembly is above or 
below the required level. 



When the amount of toner in the hopper 
is sufficient, the sensor output is "1". When 
it is below the specified level, the output is 
"0". 

The DC controller checks for 5 seconds 
after copying is completed if the TONER 
EMPTY signal (TEP) is being outputted. If 
the signal is outputted continuously for 5 
seconds, it is regarded as "TONER OUT- 
First time". If another TONER EMPTY signal 
is received in the same way after the next 
copying operation is completed, it is 
regarded as "TONER OUT-Second time", 
and the DC controller makes the ADD 
TONER indicator flash. 

The CT unit for this copier does not have 
a remaining toner sensor or waste toner 
sensor. 

3. Torque Limiter 

There is a torque limiter in the drive train 
between the main motor and the drum to 
stop the drum in response to a jam in the 
drum cleaner. 



Drum cleaning unit 




Pressed <3=v > Reteased 



Developing assembly 
positioning cam 

Stirrer 



Developing assembly rail unit 



Figure 3-27 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPHIME AU JAPON) 



3-27 



I OPERATIONS AND TIMING! 



H. Blanking 

1. Outline 

The area of the drum between the trailing 
edge of one copy and the leading edge of 
the next would normally act as an all black 
area and attract toner if a preventive 
measure were not taken. This measure is to 
switch the primary corona OFF and the 
primary corona assembly grid wire bias ON 
(There is no blank exposure; see page 3- 
22.) 

When the copy (cassette) size is a non- 
default size or when the copier is in the 
REDUCE mode, the light from the pre- 
exposure lamp is directed to the photosensi- 
tive drum by way of the reflecting plate to 
prevent adhesion of toner; the blank expo- 
sure shutter is moved to open the exposure 
slit making use of the movement of the lens. 



Movement of the Blank Exposure 
Mechanism 

When the copier is switched ON, the lens 
first moves in the direction of. enlarge- 
ment and then returns to the home posi- 
tion. : Next, the lens moves in the direc- 
tion of reduction for blank exposure up to 
a point that corresponds to the cassette 
size. At the time, the blank solenoid 
goes ON, and the blank exposure shutter 
moves in the direction of the arrow by 
the force of the spring. 



Blank exposure 
shutter 




(Front), 



Figure 3-29 






*<#% 



Reflector 



'€\ 



Pre-exposure lamp 




Blank exposure shutter 



Front 



Reflector 



Figure 3-28 



3-28 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REM JAN. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



■ OPERATIONS and TIMING I 



The blank exposure shutter is moved by 
the cam attached to the bottom of the 
lens when the lens moves to the blank 
exposure position, which corresponds to 
the cassette size. 

The blank solenoid (SL4) goes OFF 
as soon as the blank exposure shutter 
has moved to a cut-out to fix the shutter 
in position; cut-offs are provided for each 
cassette size. DIRECT and ENLARGE 
copies are made with the mechanism in 
this position. 



s6\\\\\\\\ 




Cut-offs 



Figure 3-30 



c. When the REDUCE mode is selected, the 
lens first returns to the home position 
and then moves to a position that 
corresponds to the selected reduction 
ratio. At the time, the blank exposure 
shutter is moved over a distance 
corresponding to the selected reduction 
ratio by the cam attached to the bottom 
of the lens to execute blank exposure. 



jffiuumnummnmmmmm™ (13 




Figure 3-31 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.0 JAN. 1992 PRINTED IH JAPAH (IHPRIME AU JAPON] 



3-29 



I OPERATIONS AND TIMING ■ 



IV. PAPER TRANSPORT 
SYSTEM 

A. Paper Pick-up Assembly 
and Feeder 

1. Outline 

When the pick-up clutch solenoid (SL1) 
engages, main motor (M1) turns the roller, 
feeding a sheet of copy paper to the 
registration rollers. The number of rotations 
of the pick-up roller varies with the length of 
the copy paper. 

The copy paper is fed by the registration 
rollers so that its leading edge is in line with 
the leading edge of the toner image on the 
photosensitive drum. It then passes through 
the transfer, separation, feed, fixing and 
delivery stages to the copy tray. 



The copy paper is sensed by paper 
sensor (Q2 and Q5). If it does not reach or 
pass the sensors within the specified period, 
the DC controller PCB judges that a jam has 
occurred and causes the JAM indicator on 
the control panel to flash. 

Cassette paper sensor, (Q11) senses 
whether there is paper in the cassette. If 
there is not, the CASSETTE PAPER EMPTY 
signal (CPEP) becomes "0", causing the 
ADD PAPER indicator on the control panel 
to go ON. 

Pick-up roller 




Control ring 
Figure 3-32 (rear) 



Paper detection signal 2 (PDP2) 



DC controller PCB 




Figure 3-33 



3-30 



COPYRIGHT© 1992 CANON INC. 



CANON MP-1 550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIMEAUJAPON) 



I OPERATIONS AND TIMING! 



2. Pick-up and Feeder Operation 



COPY START key 
ON 
V 




SCRV 

\ 


SCRV 

\ 








STBY 


INTR 


SCFW 




SCFW 




LSTR 


STBY^ 






AER 
















Main motor (M1); 
Feeder fan (FM3) 






Scanner home position sensor 
(Q3) signal 


















Pick-up clutch solenoid (SL1 ) 
























■ 










k 


Registration roller clutch (CL1) 


















I 


Pre-registration paper sensor 
(Q2) signal 


















i. 


Delivery paper sensor 


















1 ^ 




































■ 




■ s 








Figi 


j re 3-34 













COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.O JAN. 1992 PRINTED IN JAPAN (IMPRIME Al> JAPON) 



3-31 



■OPERATIONS and timing ■ 



3. Identifying the Cassette Size 

The presence/absence of a cassette in 
the cassette holder and the size thereof are 
identified by four switches (CST1 through 
CST4) provided in each cassette holder. 
Based on the combinations of the switches 



which have been actuated, the micro- 
processor recognizes the presence/absence 
of a cassette as shown in Table 3-3 and, at 
the same time, determines where to reverse 
the scanner and how to control the blank 
shutter. 



^""^-^^^ Arrangement 
Paper size ^^^^^ 




CST 
1 

(left) 






CST 
2 

1 






CST 
3 

1 






CST 

4 

(right) 




No cassette 














B5 
(182x257) 











1 


U1 

(184 to 190x265 to 267) 








1 





A4 
(210x297) 








1 


1 


B5R 

(257x182) 





1 








B4 
(257x364) 





1 





1 


A4R 

(297x210) 





1 


1 





A3 

(297x420) 





1 


1 


1 


U3 

(190 to 203x266 to 268) 













A5R 

(210x149) 










1 


U2 

(203 to 220 x 267 to 355) 







1 





Letter 8.5"x11" 
(21 6x279) 







1 


1 


STMT 5.5"x8.5" 
(140x216) 




1 








Legal8.5"x14" 
(216x356) 




1 





1 


Letter R 8.5"x1 1 " 
(216x279) 




1 


1 





Ledger R 11"x17" 
(279x432) 




1 


1 


1 



(unit: mm) 



0: SW is OFF. 
1 : SW is ON. 



Table 3-3 



3-32 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1SS0 REV.0 JAN. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



■ OPERATIONS AND TIMING I 



4. Pick-Up from Multifeeder 

The multifeeder pick-up roller is controlled 
by the main motor (M1 ). 

When the multifeeder paper sensor (Q1) 
identifies copy paper and the COPY START 
key is pressed, the multifeeder clutch (CL2) 
goes ON and the pick-up roller starts to 
rotate to pick up the paper. 

When the copy paper reaches the 
registration roller, the multifeeder clutch 
(CL2) goes OFF and the pick-up roller stops. 

At the same time, the multifeeder 
solenoid (SL3) goes ON to transmit the drive 
of the main motor (M1) to the cam 



mechanism, thereby lowering the multifeeder 
holding tray to prevent dirt on the next copy 
paper in duplex. 

The multifeeder solenoid; (SL3) goes OFF 
as soon as the first copy paper moves past 
the pre-registration paper sensor (Q2); at the 
time, the multifeeder holding tray returns to 
the normal pick-up position. 

Note: 

>:/ ! The. deg^©';p^'MrOTiri^./foX ! :pietiHUpS;5-i 
•from the multifeeder may be adjusted in 
the service mode (CW). 



DC controller PCB 



AC Driver 



1CL2 

Multifeeder clutch 




GX~ 


V / Multi- L 
yy feeder 
_. — ^/ solenoid! 


= 







Multifeeder Multifeeder tray 
paper sensor 
(01) 



Holding tray 



-Cam mechanism 



Clutch 



Figure 3-35 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1S50 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIMEAUJAPON) 



3-33 



I OPERATIONS AND TIMING! 



(Pick-up) 



(Holding plate) 

Multifeeder solenoid (SL3) ON 
ON 




Cam mechanism 



Figure 3-36 



Figure 3-37 



COPY START key 
Paper set ON 














INTR 


SCFW 


SCRW 


STBY (, 


Multifeeder paper sensor (Q1 ) 














Main, motor (M1) 












!, 


Multifeeder cluth (CL2) 






















■ 






>. 


Pre-registration paper sensor 
(Q2) 
















Multifeeder solenoid (SL3) 
















Registration roller clutch (CL1) 












■■< 



Figure 3-38 



3-34 



COPYRIGHT© 1992 CANOK INC. 



CANON 1 NP-1550 REV.O JAN, 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



I OPERATIONS AND TIMING! 



B. Fixing and Paper Delivery 
Assemblies 

1. Outline 

The upper and lower rollers of the fixing 
assembly are driven by the main motor (M1). 

The upper roller is heated by a single 
heater (H1:900W). When the surface 
temperature of the roller rises, the resistance 
of the thermistor (TH) falls, so the voltage of 
the signal that it produces FIXING ROLLER 
SURFACE TEMPERATURE signal (TH1) 
also falls. 

Whether the voltage of TH1 (analog) is 
above or below a certain level at a given time 
determines if the microprocessor of the DC 
controller makes the HEATER DRIVE com- 
mand (HTRD) "1" or "0". 

The NP-1550 is provided with the 
following three protection mechanisms: 



• The microprocessor monitors the 
voltage of TH1 and indicates 'E000' o r 'E001' 
in response to an error, i.e., ACOFF goes '0' 
to turn the relay (S105) OFF, thereby cutting 
the power to the fixing heater. 

• The fixing roller error detection circuit 
monitors the voltage of TH1 and, when it 
drops below 0.9V (equivalent of 215°C), 
turns HTRD OFF. 

• The thermo switch (TS1) goes OFF 
when the temperature of its inside rises to 
230°C to cut off the power to the fixing 
heater. 

'Trie thermo switch (TS1) cannot be 
used after its contact has opened; the 

i<;e^ht^:yplhnc>fi'y^ 
at room temperature. 



Fixing roller heater H1 
900W 
Upper fixing roller 




J317 : 2 



Delivery rollers 

Lower fixing roller 



Thermo-switch 
TS1 (F1 ) 230°C 







©i 



Thermistor (TH) 



\l 



S105 



•y?r lV/T JZ. 



J306-2 




. 24V 



HTRD | 
J304-4I 



5V 



! CWT) 24V 

L__ I 

AC driver PCB 




J306-4i 



ACOFF 



L_ r 



DC controller PCB 



Figure 3-39 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IHPRIME AU JAPON] 



3-35 



■OPERATIONS and timing ■ 



2. Operation of Fixing Assembly 
Temperature Control System 



Power switch 170°C 180°C COPY START key SCRV 



(ffl (150°C)(160°C) QJ4 



Main motor (M1); 
Scanner cooling fan (FM1) 



Exhaust fan (FM2) 



Fixing roller heater (H1) 



W^Ll^i??!?! , . j. . , Blink greeH 
(COPY START key indicatoQ ^j^^^ 



WMUP 



STBY 



Glows green 



^ 



I Z 



13 Z 



SCFW 



rV 



SCFW 



SCRV 

rV 



Glows oranqe 



w///s/////MYjy//;///y//////////s//sM 



LSTR 



STBY 



30 seconds^" 



(1 20 seconds) 



sagas aaMttttHMmnaaai 



Numbers in parentheses 
apply ,to when the CT unit 
is used. 




Figure 3-40 



Note: 

. ■■■ When the preheat mode starts in 
response to a press on the STANDBY 
key, the fixing temperature is controlled to 
15o°C. 



3-36 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIHE AU JAPON) 



I OPERATIONS AND TIMING I 



C. Jam Detection 

The copier has two sensors to sense 
whether copy paper is being fed normally. 

• Pre-registration paper sensor (Q2) 

• Delivery paper sensor (Q5) 

Paper jams can be identified by the 
microprocessor by reading signals from the 
sensors at predetermined times to check if 
paper is at or not at a sensor at that time, 
and thus identify if the paper is moving 
through the copier correctly. 

If a jam occurs, the copier memorizes the 
number of copies that have not yet been 
made and also the copier settings. This 
information is stored in the copier, even if the 
power is cut off by opening the front door in 
order to reset the copier. 

a. Multifeeder 



The microprocessor identifies a jam in 
any of the following four cases. Also, the 
microprocessor judges that there is a jam if 
one of the sensors detects paper when the 
power is switched ON. 

1 . Pick-up assembly delay jam 

If the copy paper does not reach the 
paper sensor of the pick-up assembly within 
a specified period after paper pick-up-starts, 
the microprocessor will judge that a pick-up 
delay jam has occurred, and immediately 
stop the operation of the copier. Also, the 
JAM indicator on the control panel will flash 
and a segment of the PAPER SELECT/JAM 
indicator will go ON. 



copy; 

key 


START 
ON 

r 






JAM indicator 
flashes 

T 






STBY 


INTR 


SCFW 


SCRV 


SCFW . S 


Multifeeder clutch (CL2) 














■MEI= 








<i 


JAM check 




--1 sec.-* 






— 1se< 












1 






i 


1 


Pre-registration paper sensor (Q2) 








Normal 




Abnorr 


ial 












■ 


Main motor (M1 ) 










<i 



Figure 3-41 (Multifeeder pick-up assembly delay jam) 



b. Cassette 



COPY START 
key ON 



Pick-up clutch solenoid (SL1 ) 



JAM check 



STBY INTR 



^ 



SCFW SCRV 



JAM indicator 
flashes 

i. 



SCFW 



Pre-registration paper sensor (Q2) 
signal 



Normal Ab normal 



Main motor (M1) 



Figure 3-42 (Cassette pick-up assembly delay jam) 

COPYRIGHT© 1992 CANON INC. CANON NP-1S50 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIHE AU JAPON) 



3-37 



■OPERATIONS AND TIMING I 



2. Delivery assembly stationary jam 

If the copy does not pass the delivery 
assembly paper sensor within the specified 
period after the registration roller clutch 
(CL1) operates, the microprocessor will 
judge that a delivery unit stationary jam has 



occurred, and immediately; stop the 
operation |of the copier. Also, the JAM 
indicator on the control panel will flash and a 
segment of the PAPER SELECT/JAM 
indicator will go ON. 



COPYS 
key 

1 


START 
ON 

f 










JAM indicator 
flashes 

▼ 




INTR 


SCFW 


SCRV 


SCFW 


SCRV 


s 


Registration roller clutch (CL1) 
























I 










, 


- — 7.6 sec. 

r 




Jam check 


















i 


I 


<. 


Delivery paper sensor (Q5) signal 






Normal 






Abnormal 




Main motor (M1) 












•, 



Figure 3-43 Delivery assembly stationary jam (A4 size) 



3. Delivery assembly delay jam 

If the copy does not reach the delivery 
assembly paper sensor within the specified 
period after the registration roller clutch 
(CL1) has operated, the microprocessor will 
judge that a delivery assembly delay jam has 



occurred,; and immediately stop the 
operation ;of the copier. Also, the JAM 
indicator on the control panel will flash and a 
segment of the PAPER SELECT/JAM 
indicator will light. 



COPY START 
key ON 



JAM indicator 
flashes 



1 


r 








▼ 






INTR 


SCFW 


SCRV 


SCFW 


SCRV 


<> 


Registration roller clutch (CL1) 












t. 


Jam check 




— — 5.4 sec. — 


T 


— 5.4 sec.— 










■ 




I 


". 


Delivery paper sensor (Q5) signal 






(Normal 




Abnormal 




Main motor (M1 ) 












*. 



Figure 3-44 Delivery assembly stationary jam (A4 size) 



3-38 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.I SEPT. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



■operations and timing ■ 



V. POWER SUPPLY 

A. AC Driver DC Power 
Supply 

1. Outline 

The AC driver/DC power supply PCB is 
supplied with AC power when the door 
switch (SW2) and the power switch (SW1) 
go ON. 

On the other hand the DC power supply 
supplies the main body with 36 VDC, 24 
VDC, and 5 VDC. 

36 VDC is used to drive the scanner 
motor (M2), and 24 VDC is used to drive 
fans and solenoids as well as high-voltage 
transformer (HVT); 5 VDC is used by the 
sensors and ICs on the DC controller PCB. 

2. DC Power Supply Circuit 

The AC voltage is lowered to 32 V by the 
external transformer (T1 ) and sent to the DC 
power supply/AC driver PCB. 

The lowered voltage is then rectified to 36 
VDC and converted to 24 VDC and 5 VDC 
by two regulators. 

These regulators serve to prevent 
overcurrent and help maintain the output 
voltage against fluctuations in the voltage of 
the power supply. 

The DC power supply/AC driver PCB is 
equipped with a zero-cross (ZXDP) signal 
generator circuit; the circuit generates zero- 
cross signals and sends them to the DC 
controller for control of the fixing heater 
temperature and the copying sequence. 

'E261' is indicated on the control panel 
when an error is identified in the zero-cross 
(ZXDP) signal. 

3. AC Driver Circuit 

The DC power supply/AC driver PCB has 
AC driver circuit and, based on the signals 
from the DC controller PCB, controls the 
SSRs and relays on the DC power 
supply/AC driver PCB to drive AC loads. 

If the DC controller PCB detects an error, 
the ACOFF signal is generated to turn the 
relay (S105) on the DC power supply/AC 
driver PCB OFF, thereby shutting off the 
power to the CVR and the fixing heater. 

When the power is shut off, switch the 
copier OFF, and identify the cause; then, 



switch the copier OFF. 

Note that repeated short-circuiting and 
resetting can cause the built-in fuse to blow. 



COPYRIGHT© 1992 CANON INC. 



CANON HP-1SS0 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



3-39 



■ OPERATIONS AND TIMING ■ 



Main motor 

CVR 

Fixing heater 



AC load 



Sorter power 




ADF power 


supply 




supply 


(option) 




(oplion) 



Door 
., Power sw jt cn Circuit breaker 
switch (SW2) (CB1) 
(SW1) 




AC driver/DC power supply PCB ' DC controller PCB 



Figure 3-45 



3-40 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IUPRIME AU JAPON) 



I OPERATIONS AND TIMING! 



VI. SERVICE MODE 

A. Outline 

The NP-1550's service mode allows the 
following: 

• checking the operation of some switches 
and LEDs. 

• changing data in EEPROM 

B. Using the Service Mode 

1) Detach the VR cover from the rear of the 
left cover. 

2) Check that the COPY START key is 
glowing green. 

3) Press the service switch (SW300) on the 
DC controller PCB. 

4) Check that ' CD ' is indicated. 

5) Enter the No. of the desired service mode 
using the NUMERIC keypad on the 
control panel. 

• For example, the display indicates ' C3 ' 

in response to a press on '3'. 

6) Press the SORT/GROUP key. 

7) Operate as follows as necessary. 

(Mode No. CO , CI I , or CIH > 

A press on the SORT/GROUP key 
executes the selected mode; a second 
press stops the execution. 

< Mode No. C J through C6 and C IS > 
Change the setting using the NUMERIC 
keypad, and press the SORT/GROUP key; 
the setting will be stored in EEPROM. 

(Mode No. CJS > 

Press the AE key twice, and check 
'CEE' is indicated on the control panel; 
then, press the SORT/GROUP key. 

8) Press the service switch (SW300) to 
leave the service mode. 



COPYRIGHT© 1992 CANONINC. CANON NW550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IHPRIUE AU JAPON) 3 - 41 



■OPERATIONS AND TIMING ■ 



C. Guide to Service Mode 



Mode No. 


Display 


Default 


Remarks 


Settings 


CD 


AE sensor output 


— 


Use it when adjusting the AE 
reference point/slope; see p. 3-46. 


CI 


AE adjustment 


25 


A higher setting causes copies of 
newspaper to become lighter; 
see 3-46. (unit: 0.1V) 


0to50 


CS 


Leading-edge registration 
adjustment 
(registration roller ON 
timing adjustment) 


32 


A higher setting delays the 
registration roller ON timing, 
(unit: 0.25 mm) 


0to63 


C3 


Leading-edge nonimage 
width adjustment 
(grid bias switch timing 
adjustment) 


32 


A higher setting increases the leading 
edge non-image width, 
(unit: 0.25 mm) 


0to63 


CM 


Degree of arching 
(multifeeder pick-up; clutch 
off timing adjustment) 


32 


A higher setting delays the 
multifeeder clutch OFF timing, 
(unit: 0.25 mm) 


0to63 



3-42 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REM JAN. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON] 



■ OPERATIONS AND TIMING ■ 



Mode No. 



C5 



LO 



r t < 

t_ 4 4 



ns 



as 



Display 



as 



Leading edge registration 
adjustment (2nd page in 
page separation; registration 
roller ON timing adjustment) 



CIB 



Leading edge non-image 
width adjustment (2nd page in 
page separation; grid bias 
switch timing adjustment) 



Default 



Settings 



32 



0to63 



32 



0to63 



Remarks 



Cassette size 



LED ON check (on cotroll 
panel) 



AE mode setting 



For factory adjustment 



EEPROM reset 



0or1 



A higher setting advances the 
registration roller ON timing, 
(unit: 0.25 mm) 



A higher setting increases the 
leading edge non-image width, 
(unit: 0.25 mm) 



The size of the cassette is indicated 
in code in response to the output of 
the activated cassette switch; 
see Table 3-4. 



Selects/Deselects the AE mode at 
time of power-on: 1 , AE ON; 2, AE 
OFF. 



0to5 



Do not change the setting; 
i.e., keep it '0'. 



Initializes EEPROM on the DC 
controller PCB. 



COPYRIGHT© 1992 CANON INC. 



CANON MP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IUPRIHE AU JAPON) 



3-43 



I OPERATIONS AND TIMING! 



Code 


Cassette size 


Code 


Cassette size 





No cassette 


9 


U1 


1 


B5 


10 


U2 


2 


U3 


11 


Letter 


3 


A4 


12 


STMT-R 


4 


B5-R 


13 


Legal 


5 


B4 


14 


Letter-R 


6 


A4-R 


15 


11 x17 


7 


A3 


16 


Muitifeed 


8 


A5-R 







Table 3-4 Cassette Size Codes 



3-44 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 AEV.0 JAN.I992 PRINTEDINJAPAN(IMPRIIIEAUJAPON) 



■ OPERATIONS and timing I 



D. Adjustment 

1. Image leading edge non- 
reproduced area 

There is a white strip on the bottom of the 
copyboard glass in the position shown in the 
figure below. If bias is being applied to the 
grid of the primary corona while the scanner 
is passing the white strip, the leading edge of 
the copy will be reproduced blank. If the 
leading edge non-image width is outside the 
standards, adjust the timing at which the grid 
bias goes from OFF to ON in the service 
mode (C3 ). 



, White strip 




-t— Approx. 10mm 

Figure 3-46 



The standard image leading edge non- 
reproduced area on a DIRECT copy of a test 
sheet is 2.0 ±1.5 mm. 




2.0 + 1.5mm 



Figure 3-47 



A higher setting ( C3 ) increases the 
leading edge non-image width; in units of 
0.25 mm. 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.1 SEPT. 1 992 PBINTEO IN JAPAN (IMPH1HE AU JAPOM) 



3-45 



I OPERATIONS AND TIMING! 



2. AE adjustment 

Make the following adjustments when the 
AE sensor or the DC controller PCB has 
been replaced. 

1) Remove the potentiometer cover at the 
back of the left cover. 

2) Set the power switch ON. 

• Wait until the WAIT period has ended. 

3) Place an NB-3 or NA-2 test sheet on the 
copyboard, and lower the copyboard 
cover. 

4) Press switch SW 300 on the DC controller 
PCB. 

• " CD " will appear on the COPY COUNT/ 
RATIO indicator on the control panel. 

• If " CD " does not appear, press the "0" 
number key on the control panel so that 

" CD " appears. 

5) Press the SORT/GROUP key on the 
control panel. 

• The scanner will move forward to the 
AE measuring position, then the scanning 
lamp will go ON. (Note) 

6) Adjust VR301 on the DC controller so that 
"22" appears on the COPY COUNT/RATIO 
indicator. 



For reference: 
£ 7.7+ 




8) Remove the test sheet, place a sheet of 
newspaper on the copyboard, and lower 
the:copyboard cover. 

9) Press the SORT/GROUP; key. 

• The copier will perform the same opera- 
tions as described in step 5). 

10) Make a note of the numerical value dis- 
played on the COPY COUNT/RATIO 
indicator. 

11) Press the SORT/GROUP key. 

• " CO " will appear on the COPY COUNT/ 
RATIO indicator. 

12) Press the "1" number key. 

" CJ " will appear on the COPY COUNT/ 
RATIO indicator. 
13) Enter the value recorded in step 10) 
using the NUMERIC keypad. 



7.7' 



♦ 


o 


r~ 


' /' 




/ 










1 / ' 












If 





-+- 



■ Document density 



Test sheet Sheet of newspaper 
|=> : when the setting is lowered. 
^ : when the setting is raised. 

Figure 3-49 



1 1 

Test sheet Sheet of newspaper 



• Document density 



Figure 3-48 



7) Press the SORT/GROUP key. 

• The scanning lamp will go OFF, and 
the scanner will return to the HOME posi- 
tion. 



3-46 



COPYRIGHT© 1992 CANON IMC. 



CANON NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



I OPERATIONS AND TIMING! 



VII. SELF DIAGNOSIS 

The DC controller PCB has a micropro- 
cessor that diagnoses the functions of the 
copier (particularly the sensors) at appropri- 
ate intervals. If this microprocessor detects 
an abnormality, it will display the type of the 



abnormality on the indicator on the control 
panel. 

The table below shows the various fault 
codes, their meaning, and the corresponding 
detection timing. 

Example of E000 code indication: 

E O ODD ''9 nt alternately. 



Code displayed 


Main cause 


Fault criteria : , 


ECCO 


Thermistor (TH1), Fixing roller heater 
(H1), AC driver/DC power supply 
PCB, DC controller PCB, operation of 
thermoswitch 


• If the temperature ol the fixing rollers after 40 seconds is 
virtually the same as when the copier is turned ON. (This 
indication does not appear if warm-up is completed within 
30 seconds.) ' 

• If the temperature of the fixing roller drops below 1 00°C for 
0.1 seconds or longer after warm-up is completed. 


EDu i 


Defective thermistor (TH1), AC driver/ 
DC power supply PCB, Fixing roller 
heater (H1 ),or DC controller PCB 


If the temperature remains 220°C or higher for 0.1 seconds or 
longer. 


E03D 


Counter, DC controller PCB 


If the break signal is emitted continuously for 0.1 seconds or 
more the counter is not being driven. 


ESDS 


Scanner HOME position sensor (Q3), 
scanner motor (M2), motor controller 
PCB, or DC controller PCB 


1 . If the scanner is not at the HOME position (SCHP = 0) when 
the COPY START key is pressed. 

If the scanner does not return to the HOME position (SCHP 
remains 0) within 15 seconds (A4 size) after it starts to 
reverse. 

2. If the scanner is in the HOME position (SCHP = 1) when the 
COPY START key is pressed. 

• If the scanner does not leave the HOME position (SCHP 
remains 1 ) within 1 .5 second after it starts to advance. 

• If the scanner does not return to the HOME position 
(SCHP remains 0) within 1 second after it leaves the 
HOME position (SCHP = 0). 


EEIU 


Lens home position sensor (Q4), 
or DC controller PCB 


• If the lens does not return to the HOME position (LHP 
remains 0) within 2.5 seconds. 

• if LHP remains 1 for at least 4 seconds 


EESD 


Lamp regulater 
Scanning lamp 


At the lamp ON timing, LAON=1 is not true. 
At the lamp OFF timing, LAON=0 is not true. 


E2W5 


DC controller PCB 


If the data in EEPROM has been rewritten more than specified. 


ESEI 


AC driver/DC power supply, 
DC controller PCB 


If the mains frequency is out of the allowed range. 


EWOO 


ADF controller PCB, ADF power 
supply, or DC controller PCB 


If ADF remains for 12 seconds or longer. 


E5D0 


Sorter controller PCB or DC control- 
ler PCB 


■ If the copier does not communicate with the sorter for at least 

12 seconds. 
• If the SORTER STANDBY signal does not return within 35 

seconds after the BCR signal is outputted. 



COPYRIGHT© 199! CANON INC. 



CANON NP-1550 REM JAN. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



3-47 



■ OPERATIONS and TIMING I 



Note: 

After setf diagnosis has been 
executed, the copier may be reset by 
sWfefting it OFF and then ON unless 
•fiOOO' of/EOOT is indicated on the 
display. 



This consideration is made to prevent the 
user from resetting the copier when the fixing 
assembly has a serious fault (open 
thermistor or others) that can damage the 
assembly. 

Rest the copier as follows if 'E000' or 
'E001' is indicated: 

1 ) Detach the rear cover 

2) Press the service switch (SW300) on the 
DC controller. 

3) Check that 'P' and 'OFF' alternate on the 
control panel COPY COUNT/RATIO 
indicator. 

4) Switch the copier OFF. 



3-48 COPYRIGHT© 1992 CANOHINC. CANON NP-15S0 REV.1 SEPT. 1992 PRINTED IN JAPAN (IHPRIME AU JAPON] 



■ MECHANICAL SYSTEM I 



I. EXTERNALS 
A. External Covers 




© Copyboard cover © Control panel 

© Left cover © Front door 

© Delivery cover © Cassette 
® Copyboard glass 

Figure 4-1 




Note: 

Make sure that the copier's doors are 
Clbsed before detaching the copyboard 
[glass. Use: alcohol when cleaning the 
■ gliss; do not use solvent, or the white 
paint along the right edge of the glass 
#ay nielt. 



1. Detaching the Inside Cover 

1 ) Remove the two screws that hold the 
front cover bands in place. 

2) Remove the screw, and detach the fixing 

assembly knob. 

3) Remove the four mounting screws, and 
detach the inside cover. 




© Front cover bands 
© Fixing assembly 
knob 



© Inside cover 

mounting screw 
© Inside cover 



Figure 4-3 



© Right cover @ Rear cover 

© Rear upper cover © Right door 

Figure 4-2 



Detach the covers as necessary when 
cleaning, checking, or repairing the inside of 
the machine, covers that can be detached by 
mere removal of the fixing screws are omitted 
from the discussions. 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550REV.0 JAN. 1992 PRINTED IH JAPAN (IMPRIME AU JAP0N) 



4-1 



I MECHANICAL SYSTEM ■ 



2. Detaching the Right Door 

1) Open the right door. 

2) Disengage the two hooks. 




©Hook 



Figure 4-4 



3) Detach the right door as if to lift it out of 
the cut-offs. 




rn~T77UF > 



© Right door © Cut-offs 

Figure 4-5 



B. Control Panel 

1 . Detaching the control panel 

1 ) Detach the inside cover. 

2) Remove the five screws, and lift the con- 
trol panel toward the front to detach. 




© Screws © Control panel 

Figure 4-6 



3) Lift the control panel to the front, and turn 
it over. 

Note; "'■;■;*?:: j 

Do not force the control panel, or the 
harness connected to it may snap off. 




© Control panel 



Figure 4-7 



4-2 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



I MECHANICAL SYSTEM! 



C. Copyboard Cover 

1 . Replacing the Copyboard Sheet 

The copyboard sheet is attached to the 
copyboard cover using adhesive tape and 
can be detached by pulling at its corner. 

After replacement, make sure to even out 
the sheet for even contact. 



D. Fans 

1. Outline 

The NP-1550 is equipped with three fans 
to circulate the air inside the machine, there- 
by preventing the machine from overheating. 

Each fan serves the following function. 

Scanner cooling fan (FM1): cools the scan- 
ner feeder fan 
Exhaust fan (FM2): discharges air to the 

outside. 
Feeder fan (FM3): transports copy paper 



2. Scanner Cooling Fan (FM1) 

1 ) Detach the rear cover. 

2) Cut off the harness band as necessary. 

3) Disconnect the connector (J309) from the 
DC controller PCB. 

4) Remove the three screws, and detach the 
scanner cooling fan. 




© Connector (J309) 
© Scanner cooling fan 



Figure 4-9 




Figure 4-8 



3. Exhaust Fan (FM2) 

1) Open the front door, and detach the drum 
unit. 

Detach the rear cover. 
Disconnect the connector (J311), and remove 
the two screws from the DC controller 
PCB; then, shift the DC controller PCB. 
Remove the two screws from the rear of 
the exhaust fan. 



2) 
3) 



4) 




Screws 



Figure 4-10 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IUPRIHE AUJAPON) 



4-3 



• MECHANICAL SYSTEM I 



5) Detach the ozone filter and the inside 
cover; then, lower the feeder assembly. 

6) Hold the exhaust fan assembly on its bot- 
tom, and remove the two screws; then, 
pull the assembly to the front. 



4. Feeder Fan (FM3) 

Seep.4-17. 




© Screws 



© Exhaust fan 
Figure 4-11 



4-4 



COPYRIGHT© 1992 CANON INC. 



CANON ;NP-15S0REV.O JAN.1992 PRINTED, IN JAPAN (IMPRIME AU JAPON) 



I MECHANICAL SYSTEM! 



II. DRIVE SYSTEM 
A. Lens Drive Assembly 

The unit is adjusted at the factory with 
high precision using special tools. Do not 
remove parts or loosen screws other than 
those discussed. 



Lens pulley 

4 turns ^d V^ 




Lens pulley fixing plate 



Figure 4-12 



COPYRIGHT© 1992 CAN0N1NC. 



CANON NP-1550REV.0 JAN, 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



4-5 



■ mechanical SYSTEM I 



1 . Detaching the Lens Cable 

1) Detach the copyboard cover, copyboard 
glass, lens cover, rear cover, and upper 
rear cover. 

2) Remove the three screws shown in 
Figure 4-13, and detach the upper frame. 




© Screws 



Figure 4-1 3 



3) Mark the position of the pulley mount and 
the cable mount using a scriber. 

4) Remove the two screws that hold the pul- 
ley mount in place. 

5) Detach the cable. 



2. Routing the Lens Cable 

1 ) Remove the tow screws that hold the lens 
pulley mount in place, and detach the 
lens pulley; see Figure 4-12. 




® Screws 
(D Pulley: 



2) Wind the lens cable around the lens pul- 
ley as shown in Figure 4-12; then, fix it 
using two screws. 

3) Shift :the pulley mount to the position 
marked with a scriber, and fix it in place 
using two screws. 



4-6 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.0 JAN. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON] 



I MECHANICAL SYSTEM I 



B. Scanner Drive Assembly 



CD- 



Pulley 2 



Pulley 3 




Screw A 



Figure 4-15 Scanner Drive Assembly 



1. Detaching the Scanner Cable 

1) Mark the position of the mount, and 
loosen screws B (2 pes.), which hold the 
mount in place. 

2) Loosen screw A (1 pes.), and detach the 
scanner cable. 



2. Attaching the Scanner Cable 

1) Route the scanner cable as shown in 
Figure 4-1 5. 

2) Position the fixing plate where a mark has 
been put using screw A. 

3) Tighten screws B. 



COPYRIGHT© 1932 CANON INC. 



CANON NP-1550REV.0 JAN. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON] 



4-7 



I MECHANICAL SYSTEM I 



3. Adjusting the Mirror Position 
(optical distance between No. 1 
and No. 2 mirrors) 

Adjust the position of the mirror after 
attaching the scanner cable. 

To adjust, relocate the fixing used for the 
No. 1 mirror mount; loosen the two screws. 

Note: 

■ |..4j|^;jfMe"t#ids to become slack as 
: • "(iore and more copies are made, 

requiring adjustment, 
ii. H.the horizontal reproduction ratio 

beeomes faulty because of inaccu- 
.... rate?'i|iki*|f^f)S%^^^J|i*i'lii„'. : ' 

1 and No. 2 mirrors, the images on 



-1 



- Sheet A 
-— Sheet B 





Figure 4-17 


x = y 


correct 


x > y 


move the No. 1 mirror mount into 




the direction of a 


x < y 


move the No. 1 mirror mount into 




the direction of b 



1 ) Draw a line 1 cm from both ends of copy 
paper (A4 or A3) as shown in Figure 4-16. 



-1 cm 



1 cm- 



"" Lines-' 



Figure 4-16 



2) Make a copy of the sheet on which lines 
have been drawn; call the copy obtained 
this way sheet A. 

3) Place a blank sheet of paper on the copy- 
board, and feed the sheet on which lines 
were drawn in the manual mode; call the 
delivered sheet sheet B. 

■ Sheet B will show contraction by heat. 

4) Put the left lines on sheet A and sheet B 
together, and adjust the position of the 
No. 1 mirror mount so that x and y in 
Figure 4-1 7 are identical. 



Note: ,-•, •,•;•:,.=.. 

If the distance between the No. 1 and 
No. 2 mirrors is short, the copy image will 
be enlarged; if long, reduced. 





No. 


mirror mount Fixin g screws 
(front) ^/ 




® 




cgnsD 




lb) 








— -C™ — = 





Mirror drive cable (rear) 

Figure 4-18 



4-8 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550REV.O JAN. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON] 



I MECHANICAL SYSTEM I 



4. Using the Mirror Cleaning Tool 



Mirror 6 cleaning assembly 




Mirror cleaning tool 



Mirror 5 cleaning assembly 

Figure 4-19 

5. Cleaning the No. 5 Mirror 

1) Detach the copyboard galss and the lens 
cover; then, remove the screw, and 
detach the mirror cleaning tool from the 
lens mount. 

2) Detach the lens cover, and insert the mir- 
ror cleaning tool as shown in Figure 4-20. 



Mirror cleaning tool 



No. 4 mirror 




3) Push the mirror cleaning tool against the 
No. 5 mirror as shown in Figure 4-21, 
and clean the lens by sliding it back and 
forth. 



No. 4 mirror 



Mirror cleaning tool 




No. 5 mirror 



Figure 4-21 



6. Cleaning the No. 6 Mirror 

1) Detach the drum cartridge, developing 
assembly, and dustproofing glass. 

2) Put the mirror cleaning tool against the 
mirror as shown in Figure 4-22, and 
clean the lens by sliding it back and 
forth. 



No. 6 mirror 



No. 5 mirror 




Figure 4-20 



Butted. 
Figure 4-22 



7. Lubricating 

Clean the scanner rail; then, apply lubri- 
cant evenly over it. 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550REV.O JAN.1992 PRINTED IN JAPAN (IHPRIME AU JAPON) 



4-9 



■ MECHANICAL SYSTEM I 



C. Main Motor Assembly 

1 . Detaching the Main Motor 

1 ) Detach the left cover and the rear cover. 

2) Disconnect all connectors, and remove 
the two screws from the DC controller 
PCB; then, detach the DC controller PCB. 

3) Disconnect the connector (J104) from the 
AC driver PCB. 




© AC driver PCB © Connector (J1 04) 
Figure 4-23 



4) Remove the four screws, and detach the 
main motor as if to lift it toward the front. 




©Screws © Main motor assembly 

Figure 4-24 



4-10 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REVO JAN. 1992 PRINTED IN JAPAN (IMPRIMEAUJAPON) 



I MECHANICAL SYSTEM I 



III. FEEDER SYSTEM 

A. Pick-up Assembly 

1. Detaching the U Guide Plate 

1 ) Detach the inside cover, right cover, and 
rear cover; then, detach the right door. 

2) Disconnect the two connectors, and 
remove the cable clamp; then, shift the 
power cord mount. 




© Connectors 
(2) Cable clamp 



) Screws 



Figure 4-25 



3) Remove the two screws, and detach the 
developing rail mount. 




4) Remove the screws, and! remove the two 
pins. 



® do 

17*"^ 




© Screws © Pins 

Figure 4-27 

5) Detach the gear 




©Gear 



Figure 4-28 



© Screws © Developing rail mount 

Figure 4-26 



COPYRIGHT© 1992 CAN0N1NC. 



CANON NP-1550REV.il JAN.1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



4-11 



I MECHANICAL SYSTEM I 



6) Remove the two screws, and disconnect 8) Detach the guide, if necessary, paying 
the connector; then, detach the multifeed- attention to the pre-registration paper 

er solenoid unit. sensor lever. 





© Screws 
© Connector 



) Multifeeder solenoid © Pre-registration © U guide plate 
unit paper sensor lever 



Figure 4-29 



Figure 4-31 



7) Remove the screw, and remove the pin 
found at the rear. 




© Screw 



©Pin 
Figure 4-30 



2. Detaching the Pick-Up Roller Shaft 

1) Detach the U guide plate. 

2) Detach the cassette. 

3) Detach the pick-up roller bushing found at 
the font. 




© Bushing 



Figure 4-32 



4-12 



COPYRIGHT © 1992 CANON INC. 



CANON NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIHE All JAPON) 



• MECHANICAL SYSTEM I 



4) Remove the screw, and disconnect the 
connector, if necessary; then, shift the 
AC driver/DC power supply PCB. 




© Screw 



Figure 4-33 



5) Detach the control ring from the pick-up 
roller shaft. 



6) Detach the pick-up roller bushing found at 
the rear. 




© Bushing 



Figure 4-35 



7) Shift the pick-up roller shaft to the rear, 
and detach the pick-up roller shaft from 
the right door assembly. 





© Control ring 



Figure 4-34 



© Pick-up roller shaft 

Figure 4-36 



COPYRIGHT© 1992 CANON INC, 



CANON NP-1550REV.il JAN. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



4-13 



I MECHANICAL SYSTEM ■ 



8) Detach the pick-up roller from the pick-up 
roller shaft. 




Figure 4-37 (top view) 




4. Positioning the Pick-Up Roller 

Attach the pick-up roller to the pick-up 
shaft as shown in Figure 4-40; make sure 
that the pick-up roller is fitted into the mount- 
ing hole. 



(front) 



* 



Pick-up shaft 



(rear) 
Mounting hole (inches) 

1 



netnc) \ 



Mounting hole (metric) 

Metric configuration only. 



Figure 4-38 (top view) 



Mounting holes without notation 
are inch/metric configurations. 



Figure 4-40 



5. Detaching the Multifeeder Roller 

1 ) Detach the right door; see p. 4-2. 

2) Disengage the two hooks, and detach the 
U-turn guide unit. 



3. Pick-Up Roller 

1 ) ' Detach the pick-up roller from the pick-up 
roller shaft. 

2) Detach the rubber member from the pick- 
up roller. 




© Rubber member of pick-up roller 
Figure 4-39 




CD Hook (2) U-turn guide unit 

Figure 4-41 



4-14 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.1 SEPT. 1 992 PRINTED IN JAPAN (IMPRIME AU JAPOH) 



I MECHANICAL SYSTEM I 



3) Push and turn the pad spring support 
assembly found at the bottom of the right 
door unit 90 degrees. 




© Pad spring support 

Figure 4-42 

4) Detach the pad unit. 




©Pad unit 



5) Pinch the hooks of the two bushings 
using pliers, and detach the bushings. 




© Multifeeder roller © Bushing 
Figure 4-44 

Note: 

Be sure to replace the pad also when- 
ever the multifeeder roller is replaced. 



Figure 4-43 



COPYRIGHT© 1992 CANOMINC. 



CANON NP-155OREV.0 JAN. 1992 PRINTED IN JAPAN (IHPRIME AU JAPONj 



4-15 



I MECHANICAL SYSTEM I 



B. Feeder Assembly 

1 . Feeder Assembly 

... Note; - , - >-.-. -:x,! -:•;.; ,:•::';-;.; ?■:;.•. ■■ ■„. v m vjy.-. 
Make sure that the drum unit, transfer 

corona assembly, and developing 
: assembly have been detached before 

detaching the feeder assembly. 

1 ) Release the feeder assembly. 

2) Detach the main motor assembly; see p. 
4-10. 

3) Remove the E-ring, and detach the bush- 
ing. 




© E-ring © Bushing 

Figure 4-45 



4) Detach the inside cover, and remove the 
E-ring; then, detach the bushing. 

5) Disconnect the connector, and detach the 
grounding wire (1 screw); then, detach 
the cord mount (1 screw). 




© E-ring 
© Bushing 



) Grounding wire 
) Cord mount 



6) Hold the side of the feeder assembly clos- 
er to the fixing assembly, and pull it out 
toward the front slowly as if to lift it. 




© Feeder assembly 

Figure 4-47 



2. Feeder Belt 

1 ) Detach the feeder assembly. 

2) Remove the two screws, and detach the 
rail cover found at the front. 




© Screws @ Rail cover 

Figure 4-48 



Figure 4-46 



4-16 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1 550 REV.O JAN. 1992 PRINTED IN JAPAN (IMPfllME AU JAPON] 



I MECHANICAL SYSTEM I 



3) Remove the two screws found at the front 
that hold the corona assembly rail in place. 




© Screws © Corona assembly rail 

Figure 4-49 



4) Remove the three screws, and detach 
the terminal holder found at the rear. 




® Screws © Terminal holder 

Figure 4-50 



5) Remove the two screws found at the rear, 
and detach the corona assembly rail. 




6) Detach the feeder belt. 




© Feeder belt 



Figure 4-52 



3. Feeder Fan (FM3) 

1 ) Detach the feeder assembly. 

2) Detach the two feeder belts. 

3) Remove the four rolls. 




© Rolls 



Figure 4-53 



4) Remove the four screws, and detach the 
feeder fan. 




© Screws 



Figure 4-51 



nfrTTTTmrnriTTTTrn 

Corona assembly rail Screws ©Feeder fan 

Figure 4-54 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



4 - 17 



I MECHANICAL SYSTEM I 



IV. EXPOSURE SYSTEM 

A. Exposure Assembly 

1. Detaching the Scanning Lamp 

1 ) Disconnect the power plug. 

2) Detach the copyboard glass. 

3) Remove the two screws, and detach the 
anti-glare plate. 




© Screws © Anti-glare plate 

Figure 4-55 



4) Push the lamp terminal plate (rear) into 
the directionof the arrow, and detach the 
scanning lamp. 




© Lamp terminal plate (rear) 
© Scanning lamp 

Figure 4-56 



MOtei., 4,,,,,,, -.;,,,, ... c; ., „ -- ,, ,. ...', . ■..-,-;.- , • 

•'■;. ,■• 'GQQte<tti|f^©: ; ste^ >•„ - . . ,■ 

L^/DO/'hot l^^jfi5|ie)^flfe;^iwr'.scanr' 

ning lamp, 
ii. Dry wipe the scanning lamp if it is 

soiled. 



2. Detaching the Thermal Fuse 

1) Detach the control panel and the copy- 
board glass. 

2) Hold the rear of the No. 1 mirror mount, 
and move it to the right until it is posi- 
tioned 'as shown in Figure 4-57. 



Note: 

be sure to hold its right side. 




© Screws (I) No. 1 mirror mount 

© Thermal fuse 

Figure 4-57 



3) Remove the two screws, and detach the 
thermal fuse. 



4-18 



COPYRIGHT© (992 CANON INC. 



CANON . NP-155OREV.0 JAN. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON] 



I MECHANICAL SYSTEM ■ 



B. Blank Assembly 

1. Detaching the Pre-Exposure PCB 

1 ) Detach the rear cover. 

2) Disconnect the connector (J731) from the 
pre-exposure PCB. 

3) Hold the pre-exposure PCB using pliers, 
and pull it straight out taking care not to 
damage PCB. 

2. Detaching the Blank Assembly 

1) Detach the copyboard glass, lens cover, 
rear cover, and drum unit; then, detach 
the developing assembly. 

2) Disconnect the connector (J731) from the 
pre-exposure PCB and the connector 
(J30) from the blank solenoid. 

© ® 



3) Hold the blank assembly on its bottom, 
and remove the four screws; then, pull 
out the pre-exposure unit to the front. 





© Screws 



Figure 4-59 



CD Connector (J731 ) (3) Connector (J30) 
©HVT 

Figure 4-58 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.1 SEPT. 1392 PRINTED IN JAPAN (IMPRIHE AU JAPOH) 



4-19 



■mechanical system ■ 



V. CORONA SYSTEM 

A. Drum Unit 

1. Detaching the Drum Unit 

1 ) Release the feeder assembly. 

2) Open the front door, and remove the 
screw. 




(D Drum unit (3) Developing assem- 

© Developing assem- bly release lever 
bly © Screw 

Figure 4-60 



3) Turn the developing assembly release 
lever counterclockwise. 

4) Pull out the drum unit to the front careful- 
ly. 



Note: ..... ,..,, ,,> :1 ..,, : . .,,,. i ._.., ,.,...,..., 
.Take care not tb'darhage the dftirt); 



: .Note;-i v ,v-,;v' ,., v .. ,.._..,, ........ 

" Jhe .photosensitive drum is: susceptf 1 '• 
. bleto light; exposure to evenropm hghi 
fcanleadto white spots or black 'lines'on .; 

telecopies, . ' '.'.:■ *>,:; ':■;>"'■:.• >';.":,. 



As a rule, do not switch the copier ON 
with the drum unit detached. 



Note: 

Do not press the COPY START key. 

2. Cleaning 

If the photosensitive drum is soiled, clean 
it using a flannel cloth coated with toner; do 
not use paper, lint-free or otherwise. 

.,,;NOte J;- ,;,= ,■;■■■ v-, , ;.,-, , ■ -J-,;.., , - .,;. , .-, .:.■,-..-, . , 

'v'Ot Do. not use .solvent: or dry wipe; the ,• 

;• <tryfii;,rtever use drum Gleaning. powdSr, : , , .% 



4-20 



COPYRIGHT© 1992 CANON INC. 



CANON NP-155OREV.0 JAN. 1392 PRINTED IN JAPAN (IMPRIME AU JAPON) 



I MECHANICAL SYSTEM ■ 



B. Primary /Transfer Corona 
Assembly 

1. Outline 

The photosensitive drum is surrounded by 
the primary and transfer corona assemblies. 

The primary corona assembly is equipped 
with a grid plate. 

2. Disassembly/Assembly 

a. Primary Corona Assembly 
1) Detach the drum unit. 



b. Transfer Corona Assembly Gut Wire and 
Static Eliminator 

1 ) Detach the transfer corona assembly from 
the copier. 

2) Remove the two screws, and detach the 
static eliminator, taking care so that the 
gut wire will not come off. 




Note: 

Do not expose the photosensitive 
drum to strong light; otherwise, white 
spots or black lines can occur on the 
copies. 



(D Screws 



Figure 4-62 



3) Detach the static eliminator 



2) Disengage the hook, and pull out the pri- 
mary corona assembly from the drum 
unit. 




(J) Hook ® Primary corona assembly 

Figure 4-61 




® Static eliminator 

Figure 4-63 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.0 JAN. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



4-21 



I MECHANICAL SYSTEM ■ 



c. Attaching the Primary/Transfer Corona 

Assembly Wire 
■ Primary Corona Assembly 
1) Remove the four tension springs, and 

detach the grid plate. 



4) 
5) 




Cut the twisted end of the corona wire to 
about 1j mm or less using a nipper. 
Hook the loop of the corona wire as 
shown in Figure 4-65, and lead the wire 
along the V-groove of the height adjusting 
roll. '; 

Hook the corona wire tension spring on 
the corona wire, and twist the spring 
three to four times as shown. 



Primary corona assembly 
(about 2 mm); /( O 




L d 



fenJ 



© Grid tension springs ® Grid plate 
Figure 4-64 



■ Transfer Corona Assembly 

2) Detach the gut wire from the transfer 
corona assembly; see p. 4-21 . 

3) Free about 40 mm from the corona wire 
reel (0.06 mm dia.), and form a loop at its 
end about 2 mm in diameter. 



Wind the '■capitii&jt^i$$Qi^'%'ftefa' l 
key on6e, and turn the hex key four to 
five times: then twist it to form a loop. 



Transfer corona assembly 
(about 5 mm) 




Figure 4-65 



6) Cut the excess corona wire to about 1 
mm or less using a nipper. 

7) Pick the end of the corona wire tension 
spring using tweezers, and hook iton the 
coronaj'terminal. 

Note: 

i. Make sure that the corona wire is free. 

of breaks or twists and its gold plating 

has not peeled 
ii. Make sure that the corona wire is not 

slack; normal, if the length of the; 

corona wire tension spring is 1 2 mm. 
in. Make sure that the corona wire is in 

the V-groove of the height adjusting 

roll. 



4-22 



COPYRIGHT© 1992 CANONINC. 



CANON NP-1550 REM JAN. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



I MECHANICAL SYSTEM! 



VI. DEVELOPMENT 
SYSTEM 

A. Developing Assembly 

1. Construction 



Blade mount 



Blade 




Stirring rod 
Figure 4-66 



2. Detaching the Developing 
Assembly 

1 ) Turn the developing assembly release 
lever counterclockwise. 

2) Slide out the developing assembly care- 
fully. . 

3) Hold the grip on the developing assem- 
bly, and take the assembly out the copi- 
er. 




3. Detaching the Blade, Developing 
Cylinder, and Side Seal 

1 ) Detach the developing assembly from the 
copier. 

2) Remove the screw, and detach the upper 
cover fixing plate. 

3) Detach the top cover. 

4) Remove the two screws, and detach the 
developing assembly upper cover. 




© Screws 



) Developing assembly 
upper cover 



Figure 4-68 



5) Place a newspaper on the floor, and pour 
out the toner from the developing assem- 
bly. 

6) Remove the two screws, and detach the 
blade mount together with the blade. 




© Screws 



Figure 4-69 



© Developing assem- ® Developing assem- 
bly release lever bly 

Figure 4-67 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550REV.il JAN. 1992 PRINTED IN JAPAN (IMPRIMEAVJAPON) 



4-23 



I MECHANICAL SYSTEM I 



7) Disengage the hook on the bottom, and 
detach the grip. 



J" 



• • • 



m 



© 

© Hook © Grip 

Figure 4-70 



9) Remove the two E-rings, and remove the 
two gears. 




(D ! E-rings ©Gears 

Figure 4-72 



8) Remove the three screws, and detach the 
developing cylinder holder (front), ball 
bearing, and developing roll. 



1 0) Remove the two screws, and detach the 
developing cylinder holder (rear), ball 
bearing, and developing roll. 




© © 



© Screws © Developing roll 

© Developing cylinder 
holder 




Figure 4-71 



© ® ©, 
© Screws © Ball bearing 

© Developing cylinder ® Developing roll 
holder 

Figure 4-73 



11) Detach the developing cylinder and side 
seal. 



4-24 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIME AUJAPON) 



I MECHANICAL SYSTEM! 



4. Attaching the Side Seal and the 
Blade 

1 ) Clean the surface on which the side seal 
will be attached using alcohol. 

2) Attach the side seal at the position shown 
in Figure 4-74. 

Attach the seal so that the long hole 
at its end is matched with the round hole 
of the developing assembly housing. 




Side seal 



Butted. 



Figure 4-74 

Side seal 



Developing assembly 




Side seal 
(longer) 



3) Attach all parts that have been detached 
except the blade. 

Make sure that the gear is assembled 
with the longer tooth in the groove. 




4) Force the blade mount against the devel- 
oping assembly in the direction of the 
arrow, and tighten the two screws. 



Blade mount 



Blade 




Figure 4-77 

5) Loosen the four screws that hold the 
blade on the blade mount, and tighten 
them again. 



Figure 4-75 



Note: 

Put the leading edge of the longer 

: ;:$de''SeaV:a^ft^.trWjaei^ 

;:.;Side""se:al,' af^ ; ;:attacli':them:;rniikihg sure';; 
that they are in firm contact with the 
curve of the developing assembly. 



-Note,:-,.. -;?» ^:: f >>;.'''v.;v ,..- „•„; ■•":;■.=;■:>«" 
Do not loosen the screws exclusively;*;; 

'jtjrj'tby .^de:ytti^y ; :corne;.off tMe;pfistaoJnN;f : 
ing pin found at the center. "'S'V '*■;.■ 



COPYRIGHT© 1992 CANOK INC. 



CANON NP-1550REV.0 JAN. 199! PRINTED IN JAPAN (IMPRIME AU JAPON) 



4-25 



I MECHANICAL SYSTEM I 



VII. FIXING SYSTEM 

A. Fixing Assembly 

1. Construction 

Upper separation claw 

Cleaning roller 

Upper roller 



2) Remove the three screws, and detach 
the blanking plate and the left cover. 





Lower roller 
Lower separation claw Paper guide 

Figure 4-78 

2. Detaching the Fixing Assembly 

1 ) Remove the screw, and detach the fixing 
assembly knob. 



© Screws 

® Blanking plate 



) Left cover 



Figure 4-80 



3) Disconnect the three connectors. 




© Connectors 



Figure 4-81 



© Screw (2) Fixing assembly knob 

Figure 4-79 



4-26 



COPYRIGHT© 1992 CANON INC. 



CANON HP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



I MECHANICAL SYSTEM I 



4) Remove the two screws, and slide out 
the fixing assembly. 




©Screws 



Figure 4-82 



3. Detaching the Upper Fixing Roller, 
Heater, and Lower Fixing Roller 

1 ) Detach the fixing assembly from the copi- 
er. 

2) Pull out faston A, and remove the screw; 
the heater mount plate (front) can be 
detached in this condition. 




© Faston A 
© Screw 



® Heater mount plate 

(front) 
© Faston B 



3) Pull faston B (see Figure 4-83), and 
remove the mounting screw from the 
heater mount plate found at the rear; 
then, pull out the heater mount plate 
(rear) and the heater carefully. 




© Screw 
(D Heater mount 
plate (rear) 



) Heater 



Figure 4-84 



4) Remove the two screws, and detach the 
thermistor cover. 




Figure 4-83 



© Screws ® Thermistor cover 

Figure 4-85 



5) Remove the screw, and detach the ther- 
mistor. 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550REV.1 SEPT.1992 PRINTED IN JAPAN (IMPRIMEAU JAPON) 



4-27 



I MECHANICAL SYSTEM ■ 



6) Remove the three screws, and detach 
the thermoswitch. 




© Screws 
© Thermistor 



(D 
Thermoswitch 



Figure 4-86 



7) Remove the C-ring at the rear, and detach 
the gear. 




© C-ring ® Gear 

Figure 4-87 



8) Remove the E-ring, and detach gear A. 

9) Remove the C-ring, and detach two gears 

B. <D ' 



© E-ring 
© Gear A 




(Front) 



) C-ring 
© Gears B 



Figure 4-88 



10) Remove the two screws, and detach the 
bushing. 

p .Noto; : .- c -,,•■■'; ^.■;*. '";■;.■■■ :■..,- r ••;""-;■ ■ -iv =■'. 

and is difficult to detach; try pushing the 

;•: u^p'ef, 'fixing. folfer : ; tithe'^ottOiTi 16 facili- :. 

•-: 'late 'detachmfinfe ',;■'"• ''■'"-'• .v. 4 n"' : '■'■*■ ''.';>. ■ ■ '■: <■ 




(Front) 



© Screws ® Bushing 

Figure 4-89 



4-28 



COPYRIGHT© 1992 CANON INC. 



CAMOM NP-1550 REV.1 SEPX1992 PRINTED IN JAPAN (IUPRIHE AU JAPON) 



I MECHANICAL SYSTEM I 



11) Push the pressure spring of the lower fix- 
ing roller using a screwdriver, and detach 
the upper fixing roller. 




© Screwdriver (D Lower roller 

Figure 4-90 

1 2) Detach the lower fixing roller. 

4. Attaching the Heater and Upper 
Fixing Roller 

Attach the heater and the upper fixing 
roller as in detaching them but in reverse 
order while noting the following: 

a. Heater 

i. Do not touch the surface of the heater, 
ii. Make sure that the end bearing the man- 
ufacturer's name is to the front. 

b. Upper Fixing Roller 

i. Wrap the roller with copy paper to pre- 
vent soiling or scarring the surface of 
the roller. 

ii. Make sure that the end with two C-rings 
is to the rear. 

iii. Make sure that the two identical gears 
are used at the front. 



5. Adjusting the Nip Width (tightening 
the pressure adjusting nut) 

If the nip width is not as shown in Figure 
4-91 , turn the bolt to adjust it. 



Feed 

direction 







c 






A3 size- 




b Center of 
copy 





















Figure 4-91 

Note: 

the each end. 



Dimension 


Measure after the upper and lower 
rollers have heated up. 


b 


4.0±0.5mm 


|a-c| 


0.5mm or less 



Table 4-1 



a. Measuring the Nip Width 

If the roller is not heated, wait for 15 min- 
utes after the WAIT indicator has changed 
to green; then, make 20 copies before tak- 
ing measurements. 

b. Taking Measurements 

1 ) Lift the copyboard cover, and make an A3 
copy of a solid black document.. 

2) Switch the copier OFF as soon as the 

leading edge of the copy comes out of the 
copier, and open the front door and the 
delivery assembly. 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550REV.1 SEPT.1992 PRINTED IN JAPAN (IMPRIHEAUJAPON) 



4-29 



I MECHANICAL SYSTEM I 



3) Turn the fixing assembly knob counter- 
clockwise slightly, and hold it for 1 5 min- 
utes; then, turn the fixing assembly knob 
to remove the copy. 

4) Measure the width of the area where 
toner is shiny; see Figure 4-91 . 

6. Attaching the Thermistor 

Make sure that the sensor face of the 
thermistor is in even contact with the surface 
of the upper fixing roller. 



NOt8; , , ■-:=-.,-,.•-.;,»;;» , ;: ,, : , lvw: ,,, :; . 

: The' ppsittohittf the-thefmistof need 'not;} 
be : adjusted ;, : #■ Ifoiw' fipntaet • is ! not everi,:' • 
■ make sure : th$f thS "'jhifrhistor ■ sprj rig .■ is" > 
not deformed. 



Thermistor spring 




Thermistor 



Figure 4-92 

7. Attaching the Thermoswitch 

Make sure that the sensor face of the 
thermoswitch is in even contact with the sur- 
face of the upper fixing roller. 



The position of the thermoswitch need 
riot be : adjusted|;if;thei cdtft&Mis riot 'even, :■ 
• mate:sure:sthj|fthet^^ is 

raft; deformed. 



Leaf spring 




Thermoswitch mount 



Thermoswitch 



Figure 4-93 

8. Position of Paper Guide 

The position of the paper guide is adjusted 
by the paper guide mount. For this reason, 
the position of the paper guide need not be 
adjusted. 



.■Note;:!.,.,. ■■■ 

If the paper guide mount has been 
detached, the position of thepaper guide 
must be adjusted. To avoid this, do not : 
loosen the screws on the paper guide if 
necessary, mark the position on the fitihg,;. 
assembly mount using a scriber. 



4-30 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550REV.O JAN. 1992 PRINTED IN JAPAN (IMPRIMEAUJAPON) 



,^t^„ n ,,,. v ^ ,.,,,,.,,, . . ,, ,, t , ,,,, . . ,. . . 
To adjust the position of the paper 
guide, place the fixing assembly on a 
desk, and move the -paper guide so that 
the position is as shown m Figure 4-94 




9. Detaching the Cleaning Roller 

1) Open the delivery assembly. 

2) Remove the screw, and detach, the fixing 
plate. 




© Screw (2) Fixing plate 

Figure 4-95 



I MECHANICAL SYSTEM I 



3) Shift the lever, and detach the cleaning 
roller. 




© Cleaning roller (2) Lever 
Figure 4-96 



10. Detaching the Upper Separation 
Claw 

1) Open the delivery assembly. 

2) Detach the cleaning roller. 

3) Remove the two screws, and detach the 
upper separation claw assembly. 




© Screws 



) Upper separation claw 
assembly 



Figure 4-97 



4) Remove the spring, and detach the upper 
separation claw. 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIME AU JAPONj 



4-31 



■ MECHANICAL SYSTEM I 



11. Attaching the Upper Separation 
Claw 

Attach the upper separation claw as detach- 
ing it but in reverse order with the following in 
mind. 

a. Make sure that the boss on the upper 
separation claw is in contact with the 
mount as shown in Figure 4-98. 




12. Detaching the Lower Separation 
Claw 

1) Detach the delivery cover; then, open the 
delivery door, and detach the lower sepa- 
ration claw retainer. 













)p 7 ® 


° 






|[ -/~T*"~*^i 




s"h6 




¥ / \' 


~~~<^ . 




7/1 


h * ' «> / ^ ~--* K 'W\\ 


1 


gP^^-ira ^"g^ts^s^ 





© Screws 



Figure 4-98 



Figure 4-100 



b. Make sure that the upper separation claw 
assembly is fully toward the rear. If a 
scratch is noted on the upper fixing roller, 
move the upper separation claw assem- 
bly about 4 mm toward the front. 



2) Remove the springs from the lower sepa- 
ration claw. 




Figure 4-99 



© Springs 



Figure 4-101 



Apply heat-resisting grease (CK-0427) 
over the following sections on a periodical 
basis. 

a) engagement of gears (rear) 

b) gear assembly of fixing knob 



4-32 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



I. LOCATION 



I INSTALLATION I 



The location of the copier should be 
chosen based on the following 
considerations. If possible, make a visit to 
the user for a study of the site before 
delivery of the copier. 

a. The ambient temperature should be 
between 15° and 35°C and the humidity, 
1 0% to 80%. Avoid locations near water 
faucets, humidifiers, water boilers, and 
refrigerators. 

b. Avoid locations near open fire or subject 
to dust or ammonia fumes and direct 
rays of the sun. Provide curtains over 
the windows if necessary. 

c. Choose a well-ventilated place. 

d. Make sure all feet of the copier will be in 
contact with the floor. 

e. Allow at least 10 cm from any wall to 
provide access. 



10 cm min. 



1.5 m min. p Copier 



- 2 m min.- 



Figure 5-1 



1.5 m min. 





10 cm min. 




iB 'i 


Copier 


] 





-2.5 m min.- 





Figure 5-2 (with sorter) 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REVO JAN. 1992 PRINTED IN JAPAN (1MPRIME AU JAP0N) 



5-1 



■ INSTALLATION! 



II. UNPACKING AND INSTALLING THE COPIER 



When a piece of metal is moved from a cold place to a warm place, droplets of water form 
on its surface. This phenomenon is known as condensation and affects the performance of 
machines. The simplest way to eliminate condensation in 'the copier, any machines for that 
matter, is to leave it alone until it warms to room temperature (at least one hour). 

A. Unpacking 



Step 



Work 



Open the shipping carton. 



Place the hands beneath the front and 
rear of the base plate of the copier (on 
skids), then raise the copier and place it 
on a pedestal or a desk. 



Open the cardboard box, and take out the 
parts and accessories. 



Remove all tape, and take out the cas- 
settes; remove the cushion blocks from 
inside the cassettes. 



Remove the tape that secures the optical 
unit in place (outside the left cover), and 
slide the fixing to the right and pull it out. 



Remarks 



Check that the following are available: 

• Copy tray 

• OPERATOR'S MANUAL 

• Drum unit 



Tape Fixing for optical unit 



Open the front cover, and disengage the 
developing assembly, and remove it from 
the copier. 




Check that the developing cylinder is free 
of scratches. 



5-2 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIMEAUJAPON) 



I INSTALLATION ■ 



Step 



Work 



Remarks 



Remove the cushion blocks from the 
feeder assembly and fixing assembly. 




Cushion blocks 



Pull the spacer (if found*) to the front to 
detach. 

'Some previous machines may not have it. 




Spacer 



Disengage the feeder assembly, remove 
the knob, and remove the dummy drum. 

Keep the knob for use later. 




10 



Remove the lens lock screw (w/ shipping 
tag) from between the drum unit rails of 
the copier. 




COPYRIGHT© 1992 CANON INC. 



CANON NP-15S0 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIMEAUJAPON) 



5-3 



■ INSTALLATION I 



Step 



Work 



Remarks 



11 



Open the delivery cover, and remove the 
two fixing roller release rolls; then, close 
the delivery cover. 




Release rolls 



B. Mounting the Drum 

The photosensitive drum is susceptable to light; if exposed to room light, it can cause white 
spots or black lines on the copy images. As such, be quick in performing the following work. 



Step 


Work 


Remarks 


1 


Take out the drum unit from the box, 
and remove the light-blocking sheet. 


Drum unit 

Light-blocking \ ^-j^- ^V 

sheet i ^-y^^f^^ . x. 

Take care not to damage the drum. 


2 


Set the drum unit in the copier, and fix it 
in place using the knob that held the 
dummy drum. 


Slide the drum unit straight along the rails 
into the copier 


3 


Move the grip to clean the corona wire 
of the drum unit two to three times. 




4 


Set the developing assembly in the 
copier, and engage it. 


The front cover may be left open. 



5-4 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.1 SEPT. 199! PRINTED IN JAPAN (IMPRIME AU JAPON) 



> installation! 



C. Checking the Operation 



Step 


Work 


Remarks 


1 


Turn the door switch ON using the door 
switch actuator. 




2 


Connect the power plug, and shift the 
POWER switch to 'ON'. 


Check that the ADD PAPER and CAS- 
SETTE OUT indicators go ON and the 
WAIT indicator lights red. 


3 


Set the cassette size to suit the needs of 
the user. 


See p. 5-8 


4 


Put copy paper in the cassette, and set 
the cassette in the copier. 


• Check that the ADD PAPER indicator goes 
OFF. 

• Press the keys, except the COPY START 
key, on the control panel, and check 
that each operation is correct. 


5 


Set the copy tray on the copier. 




6 


Open the copyboard cover, and remove 
the paper and the protection seal from the 
document size plate. 




7 


Record the reading of the copy counter. 




8 


Make a copy after the COPY START key 

has gone green. 

Wait for 1 ten seconds or more after the 

drum has stopped, and make another 

copy- 


Check the following: 

• No abnormal sound is heard; and 

• The ADD TONER indicator flashes about 
five to ten seconds after the second 
copy operation is over. 


9 


Check that the counter operates properly. 


Check that the reading has increased by two 
from the reading recorded in step 7. 



COPYRIGHT© 1992 CANON INC. 



CANON NP-15S0 REV.0 JAN. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



5-5 



I INSTALLATION I 



D. Adding Toner 



Step 



Work 



Remarks 



Remove the door switch actuator. 



10 



11 



Disengage the developing assembly, and 
slide it until it stops. 



Shake the toner cartridge well. 



Open the developing assembly lid, and fit 
the boss on the rear end of the toner 
cartridge into the hole of the plate on the 
rear end of the developing assembly; 
thereafter, pull the toner cartridge to the 
front somewhat so that it comes into 
contact with the boss found on the left 
side of the front. 



Hold the toner cartridge, and pull on the 
seal to the front until it stops. 



Tap lightly on the top of the toner 
cartridge until all toner has fallen 
into the developing assembly. 



Remove the toner cartridge, and keep it 
in an empty box. 



Close the developing assembly lid, and 
slide the assembly inside until it stops. 



Turn the developing assembly lever 
clockwise to engage it. 



Close the front cover. 



Set a blank sheet of paper (A3/1 1"x17") 
on the copyboard after the COPY START 
key goes green, and make six to ten 
copies. 




The operation causes the toner inside the 
developing assembly to be stirred. 



5-6 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.1 SEPT. 1 992 PRINTED IN JAPAN (IMPHIME AU JAPON) 



E. Checking the Image 



I INSTALLATION! 



Step 


Work 


Remarks 


1 


Place the Test Sheet on the copy- 
board, and check the image. 


Check that copies are made without a problem 
and the non-image width along the leading 
edge is correct; otherwise, make adjustments. 
Non-image width: 

2.0 mm (approx.) for leading edge 
2.5 mm (approx.) on left/right side 


2 


Feed paper in the manual mode. 


Make tow-sided and overlay copies, and check 
that the operation is correct; otherwise, make 
adjustments. 


3 


Put the OPERATOR'S MANUAL in the 
pocket of the copyboard cover. 




4 


Clean up the area around the copier, 
and fill out the Service Sheet. 





When all above work is finished, install the options(ADF-A1 , MS-A1 , Stapler Sorter-B1 , 
and Control Card V) and the document holder. 



■ Points to Note for Photosensitive Drum 
After Installation 

The photosensitive drum is susceptible to 
light and, if exposed to light, can cause 
white spots or black lines on the copy 
image; take note of the following: 

• Limit the replacement of the CT unit within 
one minute; 

' • Limit the removal of jams within five 
minutes; and 

• Keep the drum wrapped in the light- 
blocking sheet (from drum unit) or fresh 
copy paper and place ;it in a dark place 
whenever it is removed from the copier. 



Do not touch the drum; if its surface is 
soiled, wipe off the dirt using a flannel cloth 
coated with toner. Do not use paper, lint- 
free or otherwise, or use a dry cloth or 
solvent. 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.O JAN. 1992 PRINTED IN JAPAN (IMPRIMEAUJAPON) 



5-7 



I INSTALLATION I 



III. SETTING THE 
CASSETTE SIZE 

The copier's cassette may be modified to 
suit the desired paper size by modifying the 
rear stop plate, spring, and face plate. 

1. Modifying the Cassette Size 

1) Turn over the cassette, and remove the 
screw that holds the rear stop plate in 
place. 



Screw 



Bottom of cassette 




Figure 5-3 



2) Change the rear stop plate to suit the 
desired paper size; note the index on the 
bottom, and see Table 5-1 . 



For the following, use two rear stop 
plates, note the index on the bottom of 
the cassette B4, A4-R, LGL ARG-R, 
11x17, LTR-R.FLS, G.R, FOLIO, G.LGL, 
AUS. FLS, BLV., ARG.LGL.E., OFC 



Copy paper 



A3 



11x17 



A4 



Government Letter 



Korean 



Legal 



B5 



Argentine Letter 



A4-R 



Letter-R 



B5R 



Argentine Legal 



Government Letter-R 



Government Legal 



Argentine Letter-R 



Foolscap 



Folio 



Size 



297mmx420mm 
(11.7"x16.5") 



279.4mmx431.8mm 
(11"x17"), 



210mmx297mm 
(8.3"x1 1 .7") 



216mmx279mm 
(8.5"x11.0") 



203mmx267mm 
(8"x10.5") 



190mmx265mm 
(7.5"x10.4") 



257mmx364mm 
(10.1"x14.3") 



216mmx356mm 
(8.5"x14.0") 



182mmx257mm 
(7.2"x10.1") 



220mmx280mrh 
(8.7"x11.0") 



297mmx210mm 
(1 1 .7"x8.3") 



279mmx216mm 
(1 1 .0"x8.5") 



257mmx182mm 
(10.1"x7.2") 



220mmx340mm 
(8.7M3.4") 



267mmx203mm 
(10.5"x8.0") 



203mmx330mm 
(8.0"x13.0") 



280mmx220mm 
(11.0"x8.7") 



216mmx330mm 
(8.5"x13") 



Australian Foolscap 



Korean-R 



Officio 



Ecuadoreah 
Officio 



Bolivian Officio 



210mmx330mm 
(8.3"x13") 



206mmx337mm 
(8.1"x13.3") 



265mmx190mm 
(10.4"x7.5") 



216mmx317mm 
(8.5"x12.5") 



220mmx320mm 
(8.0"x12.6") 



216mmx355mm 
(8.5"x14.0") 



Table 5-1 



Rear stop 
plate 



A3 



11x17 



A4 



LTR 



LGL 



B5 



Arg. 



A4Q 



LTRU 



B50 



Arg. LGL 



G.LGL 



Arg.El 



FLS 



FOLIO 



Aus.FLS 



OFC 



5-8 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.O JAN. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



I INSTALLATION! 




Rear stop plate 



Figure 5-4 



6) Slide the paper size plate along the index 
on the bottom of the cassette to suit the 
desired paper. 



Paper size plate 




Figure 5-6 



3) Fix the stop plate in place using screws. 

Note; 

£^ "Replacing trie Cassette Spring" 
whfn'rbtsirig/a diffeiferrt-type.of; spring. 



4) Remove the side stop plate each from the 
two cassettes. 



7) Place about 100 sheets of paper (fresh 
out of package, of the desired size) in the 
cassette, and butt them against the front 
of the cassette. 

8) Keep the side stop plate between the 
bunch of sheets and size plate as shown, 
and screw the size plate using a screw; 
make sure that the size plate is butted. 



Side stop plate 




Size plate 



Shift the leaf spring in 
this direction to remove 
the side stop plate 



Figure 5-7 



Figure 5-5 



5) Remove the screw that hold the paper 
size plate in place. 



9) Fix the side stop plate in its original 
location. 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.0 JAN. 1992 PRINTED IN JAPAN (IMPRIMEAUJAPON) 



5-9 



I INSTALLATION ■ 



1 0) Set the cassette size tab. 



Cassette 



Tab 





© © 



Copy paper 
size 


Tab No. 


© 


® 


© 


© 


B5 


□ 








U1 




D 






A4 


□ 


D 






B5-R 






□ 




B4 


□ 




□ 




A4-R 




D 


□ 




A3 


D, 


D 


□ 




U3 








□ 


A5-R 


□ 






□ 


U2 




D 




□ 


LTR 


□ 


□ 




□ 


STMT-R 






□ 


□ 


LGL 


□ 




□ 


□ 


LTR-R 




□ 


□ 


D 


11 x17 


□ 


q 


□ 


□ 



□ • • • • tab present 
U1 : Korean-R 



Figure 5-8 



U2: Others 

U3: Korean, Argentine Letter, 
Government Letter. 



5-10 



COPYRIGHT© 1992 CANON INC. 



CANON HP-1SS0 REV.0 JAN. (992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



I INSTALLATION I 



11) Detach and attach the plate; see Table 
5-2. 



Copy paper size 


Face plate 


A3 


abed 


11x17 , 


abed 


A4 


abed 


Letter 


abed 


Argentine Letter 


abed 


Government Letter 


abc 


Korean 


abc 


B4 


abc 


B5 


abc 


A4-R 


ab 


Letter-R 


ab 


Argentine Legal 


ab 


Government Letter-R 


ab 


Government Legal 


ab 


Arqentine Letter-R 


ab 


Foolscap 


ab 


Folio 


ab 


Australian Foolscap 


ab 


Officio 


ab 


Ecuadorean Officio 


ab 


Bolivian Officio 


ab 


Legal 


ab 


Korean-R 


a 


B5R 


a 



Table 5-2 

Claw Face Face Face Face lnside P late 
plate d plate c plate b plate a 




2. Replacing the Cassette Spring 

• The copier can be reset for a different size 
of copies by modifying the cassette spring 
as shown in Table 5-3. 



Size of paper 


Color of spring 


A4/A3 
11x17/LTR/l 


green 


A4R/B5R/LTR-R 
LGL/STMT/II 


yellow 


B4/B5 


red 



Table 5-3 

I: ARGENTINE LTR 
GOVERNMENT LTR 
KOREAN 

II: ARGENTINE LGL 
GOVERNMENT LGL 
ARGENTINE LTR-R 
GOVERNMENT LTR-R 
FOOLSCAP FOLIO 
AUSTRALIAN FOOLSCAP 
KOREAN-R 
ECUADORAN OFICIO 
BOLIVIAN OFICIO 



1 ) Remove the rubber stopper from the 
inside plate. 

Rubber stoper 




Figure 5-10 



Figure 5-9 



12) Attach the size label on the cassette; if 
the label is not available, write the size 
on a blank strip of paper. 



COPYRIGHT© 1992 CANON INC. 



CANON NM550 REM JAN. 1992 PRINTED IN JAPAN (IHPRIHE AU JAPON) 



5-11 



I INSTALLATION! 



2) Remove the inside plate and spring. 




Figure 5-11 



3) Change the spring as shown in Table 5-3. 

4) Set the inside plate, and attach the rub- 
ber stopper. 



Inside plate 




Figure 5-12 



Check that the rubber stoppers are 
correctly attached; further, check that the 
spring at the rear is correctly set on the 
fixing behind the inside plate. 



Spring fixing 



Inside plate 



Spring 




Claw 



Cassette 



5-12 



Figure 5-13 

COPYRIGHT © 1992 CANON INC. 



3. Removing the Pick-Up Roller 

If the cassette is sized to GOVERNMENT 
LTR, KOREAN, or KOREAN-R, remove the 
pick-up rollers shown below (metric rollers). 

• GOVERNMENT LTR and KOREAN 




Figure 5-14 



KOREAN-R 




Figure 5-15 



CANON NP-1550 REVO JAN. 1992 PRINTED IN JAPAN {IMPRIME AU JAPON) 



■ INSTALLATION! 



IV. SETTING THE CT 
UNIT 

1) Hold both ends so that the yellow seal 
(round) is to the front, and turn it in the 
direction of the arrow about ten times as 
shown below. 



3) 



Put the CT unit back into the storage 
case, and roll it about ten times in the 
direction of the arrows. 





Figure 5-18 



4) Shake it in the direction of the arrows 
about ten times. 



Figure 5-16 



■■•■ ■■■■ 



2) Take the CT unit from the storage case, 
and set it in the copier; thereafter, hold 
the CT unit in place, and pull the yellow 
tab straight out. 

Note: 

Do not pull out the orange film. 






Figure 5-17 



Figure 5-19 



5) Set the CT unit in the copier once again, 
and make test copies in the DIRECT 
mode; repeat step 4) if the image is 
uneven. 

6) Set the CT unit in the copier, and pull the 
orange tab straight out; thereafter, close 
the front door. 




Figure 5-20 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REVO JAN. 1992 PRINTED IN JAPAN (IMPRIMEAUJAPON) 



5-13 



I INSTALLATION I 



V. RELOCATING THE COPIER 

Perform the following when relocating the copier by truck or other means of transportation. 



Step 


Work 


Check 


Remarks 


1 


Remove the drum unit. 


Put the drum unit in a 
box for transport. 




2 


Fix the scanner and lens in place. 






3 


Tape the corona assemblies and 
feeder assembly release lever in 
place against vibration. 






4 


Tape the front door and delivery 
assembly. 






5 


Place a sheet of A3 or 1 1 "x1 7" 
paper on the copyboard glass, and 
tape the copyboard cover. 







Table 5-4 



5-14 



COPYRIGHT© 1992 CANONIHC. 



CANON NP-1550 REV.1 SEPT.1992 PRINTED IN JAPAN (IMPRIME AU JAP0N) 



■ INSTALLATION I 



VI. SETTING CONTROL 
CARD V 

1 ) Open the front door, and remove the 
inside cover. 

2) Remove the control panel; see p.4-2 

3) Turn over the control panel, remove the 
screw that holds the face lid in place. 

4) Remove the face plate. 




© Mounting screw © Face lid 

Figure 5-21 



5) Remove the protection sheet from the 
indicator unit of Control Card V. 

6) Place the clear sheet over the hole of the 
indicator unit. 



©Hole 





© Holes for mounting 
screws 



Figure 5-23 



Check that the connector for the printer is 
found at the center of the hole. 



Figure 5-22 



© Connector for printer 

Figure 5-24 




7) Fix Control Card V on the control panel 
using four mounting screws. 

Slide a card into Control Card V, and fix 
Control Card V where the card can be slid in 
and out easily. 



COPYRIGHT© 1992 CANON IMC. 



CANON NP-1550 REV.0 JAN. 1992 PRINTED IN JAPAN (IMPRIME AU JAPONj 



5-15 



■ INSTALLATION! 



8) Attach the grounding wire for Control 
Card V. 




© Grounding wire 

Figure 5-25 



9) Disconnect the shorting connector of the 
control panel shown in Figure 5-26. 

10) Connect the 4P connector of Control 
Card V and the 4P connector of the 
control panel on the copier side. 



11) Mount the control panel on the copier. 

12) Remove the protection sheet from the 
control panel guide plate of Control Card 
V. ! 

13) Attach the control panel guide plate of 
Control Card V on the control panel of 
the copier. 




© Guide plate 



Figure 5-27 



14) Turathe copier ON, and check the 
operation of Control Card V. 

15) Attach the inside right cover. 




© Shorting connector © 4P connector 
Figure 5-26 



5-16 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.1 SEPT. 1 992 PHINTED IN JAPAN (IMPRIUE AU JAPON) 



I INSTALLATION I 



VII. ATTACHING THE 

DOCUMENT HOLDER 

1 ) Fit the two stepped screws (M4 x 5) on 
the right side plate of the copier. 




Figure 5-28 



2) Hook the retainers of the document 
holder on the stepped screws. 




Figure 5-29 



COPYRIGHT © 1992 CANON INC. 



CANON NP-1 550 REM JAN. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



5-17 



I MAINTENANCE AND SERVICING ■ 



I. PERIODICALLY REPLACED PARTS 

To maintain the copier at its peak performance, the parts listed in the following chart must be 
replaced periodically. Although the deterioration of a part may not be visible, it can seriously 
hamper the performance of the copier if not replaced on schedule. 

Parts should be replaced during the regular service visit that is closest to the end of the 
service life of the part. 











as of SEPT. 1992 


No. 


Description 


Part No. 


Quantity 


Replacement 


Remarks 


1 


Ozone filter 


FF2-5595-00P 


1 


- 


1 year 


2 


Static charge eliminator 


FF1 -9438-050 


1 


50,000 




3 


Transfer corona wire 


FY3-0040-000 


AR 


100,000: 


115/220/240V 


4 


Side seal, upper (short)(develop- 
ing assembly) 


FA5-1 790-000 


2 


100,000 




Side seal, lower (long)(develop- 
ing assembly) 


FA5-1 769-000 


2 


100,000 




5 


Front developing cylinder spacer 
roller 


FA5-1 766-000 


1 


100,000 




6 


Rear developing cylinder spacer 
roller 


FA5-1 767-000 


1 


100,000 





The above values are estimates ahft: 
are subject to change depending on 
experience. 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIME AU JAPONj 



6-1 



I MAINTENANCE AND SERVICING I 



II. DURABLE PARTS 

The values shown in the table below indicate the expected average life (number of copies) of 
parts which may require replacement at least once during the warranty period due to 
deterioration or damage but which can be simply replaced to restore the performance of the 



copie 








as of SEPT. 1992 


No. 


Description 


Part No. 


Quantity 


Service life 
(number of copies) 


Remarks 


1 


Oil-applying roller (fixing 
assembly) 


FA5- 1952-000 


1 


20,000 




2 


Scanner drive cable 


FA5-2073-000 


1 


100,000 




3 


Scanninq lamp (scanner) 


FH7-31 14-000 


1 


100,000 


220/240V 


4 


Paper pick-up roller (pick-up 
assembly) 


FC1-0676-00P 


6 


100,000 




5 


Slide scraper (developing 
assembly) 


FA5-1 768-000 


2 


100,000 




6 


Upper fixing roller bearing 
(fixing assembly) 


FS1 -1240-000 


2 


100,000 




7 


Preexposure lamp 


FG2-4048-O0P 


1 


200,000 




8 


Upper fixing roller (fixing 
assembly) 


FA5-1 91 6-050 


1 


200,000 




9 


Lower fixing roller (fixing 
assembly) 


FA6-3921-000 


1 


200,000 




10 


Upper separation claw (fix* 
ing assembly) 


FB1 -0301 -000 


5 


200,000 




11 


Lower separation claw (fix- 
ing assembly) 


FA2-9037-000 


5 


200,000 




12 


Multi feeder roller 


FC1 -0741 -OOP 


1 


90,000 


Must be replaced 
at the same time. 


13 


Pad (multi feeder) 


FC1-0736-O0P 


1 


90,000 



Note: 

The above values are estimates and 
, are subject to change depending on 
experience. 



6-2 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1S50 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIMEAUJAPON) 



I MAINTENANCE AND SERVICING I 



III. BASIC PROCEDURE FOR PERIODIC SERVICING 

i. Perform periodic servicing after every* 1&;M0«G$fiifl*<^*>9atanl wto. 
ii. Before making a service call, check the service log ancftake along any replacement parte 
that are likely to be needed. 



No. 


Procedure 


Check 


Remarks 


1 


Note the operator's 
comments. 


Conditions of copier 




2 


Record the counter reading 


Number of miscopies 




3 


Make DIRECT and two-page 
overlay test copies. 


a. Image density 

b. Dirty background 

c. Clarity of letters 

d. Leading edge blank area 

e. Left and right margins 

f. Fixing, synchronizing, and 
soiling of back 

g. Unusual noise 

h. Operation of counter 


Standard: 2.0±1 .5mm 
(DIRECT) 

Standard: 10.0±2.0mm 
(DIRECT), front side 


4 


Clean the corona 
assemblies. 




Wipe dry using lint-free pa- 
per then clean using alcohol. 


5 


Clean separation feeder 
assemblies. 






6 


Clean fixing and delivery 
assemblies. 

• Paper guide plate 

• Separation claws (upper 
and lower) 




Alcohol 


7 


Perform the periodic servic- 
ing appropriate to the num- 
ber of copies (see page 6-4). 






8 


Clean the copyboard cover 
and the copyboard glass. 






9 


Check the amount of waste 
toner. 






10 


Make test copies. 






11 


Make sample copies. 






12 


Select sample copies to keep 
for the customer record. 
Clean up around the copier. 






13 


Record the final counter 
value. 






14 


Fill in the service sheet and 
check out with the person in 
charge. 







COPYRIGHT© 1992 CANON INC. 



CANON NP-1S50 REV.1 SEPT. 1992 PHINTED IN JAPAN (IMPRIMEAUJAPON) 



6-3 



I MAINTENANCE AND SERVICING I 



IV. PERIODIC SERVICING SCHEDULE 

Note: 

|Do not use solvents or oils other than those specified. 



a: Clean •: Replace 



Lubricate a : Adjust ® : Check 



Unit 


Description 


Periodic servicing 


Remarks 


Every * 
1 5,000 
copies 


Every 
30,000 
copies 


Externals 


Copyboard glass 


A 




Clean with alcohol. 


Ozone filter 






Replace yearly. 


Scanner drive 
unit 


Scanner rails 




X 


Clean with alcohol then 
apply high-vis-cosity 
lubricating oil (TKN-0451) 


Feeder 


Transfer guide 


A 




Damp cloth 


Feeder belt 


A 




Feeder frame 


A 




Optical path 


Scanning lamp 
reflector 




A 


Clean with a blower 
brush. If very dirty, 
clean with alcohol. 
Clean mirrors 5 and 
6 with mirror clean- 
ing tool. 


Scanning lamp side 
reflector 




A 


Mirror 1 to 6 




A 


Lens 




A 


Dustproofing glass 


A 




Corona 
assemblies 


Primary corona 
assembly 


A 




Dry wipe using lint- 
free paper, then 
clean using alcohol. 


Primary corona wire 


A 




Transfer corona 
assembly 


A 




Transfer corona wire 


A 




Static charge 
eliminator 


A 




Damp cloth 


Developing 
assembly 


Developing rollers 
(front and rear) 




A 


Clean with alcohol. 


Side seals (front and 
rear) 






Fixing assembly 


Upper fixing roller 


A 




Clean with cleaning 
oil. 


Lower fixing roller 


A 




Paper guide plate 


A 




Clean with MEK. 


Separation claws 
(upper and lower) 


A 





* Items to be cleaned every 15,000 copies or over 6 months, whichever comes first. 

< Option : Stapler Sorter - B1 > 
Not designated. 



6-4 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPPJMEAU JAPON) 



Power switch 170 o C 
ON (150°C) 
V ^7 



180°C COPY START key 
(160-C) ON 

' _sz. 



Green indicatorjlights to A. GENERAL TIMING CHART 
indicate co pying pan sta rt (A4, AE, 2 COpieS) 




2 Varies depending on the reproduction ratio and the setting of 'leading edge (C3V in the service moT 

•3 ^' eS H ePen 5' nSOntheCaSSe,,eSizeandthe ^ l ^d reproduction ratio * 

3 Varies depending on ths reproduction ratio <-""" ratio. 

4 ££ ass o°n e sr-s adjustmem (c4) ■ in ,he service m °^ — - -■ 



COPYRIGHT© 1992 CANON MC. 



P 

no 



CANON NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



Generated only when the CT unit is in use to increase the intensi y of the scanning lamp 

CT unit's us™'' *"" ^ 3 ° ** ^ *° "'"* develo P in 9 asdemb| y is "sed and 120 sec when the 

Used only when the multifeeder is in use. 

Varies depending on the setting of 'leading edge non-image width' in the service mode 

Vanes depending on the cassette size. 



A-1 



<MULTI FEED> 

(A4, 2copies, multifeed) 




•Varies depending 1 ™ the setting ot 'arc adjustment (C4)' in the service mode; multifeeder in 



A-2 



COPYRIGHT© 1992 CANON INC. 



CANON NP-155OREV.0 JAN.1992 PRINTED IN JAPAN (IMPBIME AUJAPOH) 



B. LIST OF SIGNALS/COMMANDS 



1. SIGNALS 

ACBON 

ACOFF 

AE 

AE-BIAS 

AEGIN 

BLSD 

BTEP 

CCNTD 

CCNNT 

CPEP 

CSIN 

CSZO 

CSZ1 

CSZ2 

CSZ3 

CSZ4 

CTD 

DCBC 

FM1D 

FM2D 

FM3D 

GRBC 

GRDON 

HTRD 

HVTON 

LAON 

LGHT 

LHP 

LIC 

LNSD 

MFCD 

MFPD 

MFSD 

MMD 

PDP1 

PDP2 

PEXP 

PUSD 

RGCD 

RDC 

SCHP 

TCNTD 

TEP 

TH1 

ZXDP 



AC BIAS ON command 

AC SHUT-OFF command 

AE SENSOR OUTPUT signal (analog) 

AE SENSOR BIAS signal (analog) 

AE SENSOR GAIN signal 

BLANK SOLENOID DRIVE command 

BLACK TONER EMPTY signal 

CONTROL COUNTER DRIVE command 

CONTROL CARD CONNECT signal 

CASSETTE PAPER EMPTY signal 

CASSETTE IN signal 

CASSETTE SIZE signal 

CASSETTE SIZE signal 1 

CASSETTE SIZE signal 2 

CASSETTE SIZE signal 3 

CASSETTE SIZE signal 4 

CT-UNIT DETECTION signal 

DC BIAS CONTROL command 

FAN MOTOR 1 DRIVE command 

FAN MOTOR 2 DRIVE command 

FAN MOTOR 3 DRIVE command 

GRIDE BIAS CONTROL signal 

GRID ON signal 

HEATER DRIVE command 

HVTON command 

LAMP ON command 

LIGHT signal 

LENS HOME POSITION signal 

LIGHT INTENSITY CONTROL command 

LENS SOLENOID DRIVE command 

MULTIFEEDER CLUTCH DRIVE command 

MULTIFEEDER PAPER DETECTION signal 

MULTIFEEDER SOLENOID DRIVE command 

MAIN MOTOR DRIVE command 

PAPER DETECTION signal 1 (Q2) 

PAPER DETECTION signal 2 (Q5) 

PRE-EXPOSURE LAMP LINT command 

PICK-UP ROLLER CLUTCH SOLENOID DRIVE command 

REGISTRATION ROLLER CLUTCH SOLENOID DRIVE command 

RIGHT DOOR CLOSE signal 

SCANNER HOME POSITION signal 

TOTAL COUNTER DRIVE command 

TONER EMPTY signal 

FIXING ROLLER SURFACE TEMPERATURE signal (analog) 

ZERO CROSS DETECTION signal 



2. ABBREVIATIONS 

AER 

INTR 

LSTR 

SCFW 

SCRV 

STBY 

WMUP 

WMUPR 



AE ROTATION 
INITIAL ROTATION 
LAST ROTATION 
SCANNER FORWARD 
SCANNER REVERSE 
STANDBY 
WARM UP 
WARM UP ROTATION 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



A-3 



C. GENERAL CIRCUIT DIAGRAM 

2 I 1 



Transformer 



XH 



T1 



J102 



] [ 



ZK 



J110 



er/DC power supply PCB 



J107 



(ADF) (Sorter) 

J108 J109 



Q 



33 — [ill 



Si 



J601 



J602 



LA1 



ft 



J603 CT 



- ^WWY^ 



Lamp regulator UJ Scanning lamp 



3j 



I 



6A5 14 13 I 2 



X 



I 



£ 



J 



FUSE2(FU2) 
Cassette size sensor 



CST 

(SW3) 



ixn 




ra 



High-voltage transformer 

HVT 

J801 



J28 



3— EisEXixi 

J305 



DC controller PCB 



6 1 M 



Scanner motor 





FM1 



'X 2X3X^5] — [1X2X3X^X5 X eX ^iX 2X3 X ^XsXs HuzMiXzMOCzXs 



J310 



J307 



J302 



J304 J309 



J311 



^ 



DF-TXD _>^ 

df-sb r^ 

\ 6 

GND 



M 
5 



DF-ACK >~N 
'3 

GND 



J317 J303 J313 

:xo (3X4X5) (eX^Xe) ('X&kwx x*x>) (fl-x^ — toco cocox?) c ? q 



DF-RXD ^N ADF 



A 
A 



J352 



To 



J35 



I 



K 



J33 



I 



I 



Q3 Q4 

M*r Mm 

TH1 Scanner Lens 

(NTC1) home home 

?rmister position position 

sensor sensor 



I: 



£ 



U21314 



il 



4X1X2X3 



4X 1 A 2A 3 



J39L 



3l 



J701 



AE 



I 



3X2A1 



K 



'<--> 



® 



J21 
J42 



J26 FM3 




J43 



K^ "^ 



AE sensor 



Black toner Cassett e 

level sensor P a P er 
sensor 




Q5 

i>n±r 

Delivery 
Feeder paper 
fan sensor 



123d 



CNT1 



Total 
counter 



H 



G 



D 



13 



12 



11 



10 



8 



Mammotoi 
M1 




Q3 

TH1 Scanr 

(NTC1) home 

Thermister positic 

senso 



Copy density 
knob 



Power 
indicator 



Control 
card 



COWHGKT© 1992 CANON WC. 



CANOtl WM550 REV.1 SEPI 1992 PRINTED « JAPAN (WSffi AU JAPOtl) 



D. DC CONTROLLER CIRCUIT DIAGRAM 

J DC CON TRO LLER PCB (1/5) 



BPAO 



Q303 



BPA1 



R324< 



I STAC > - 



R325 

-AW- 



BPAP 3 



D330 
- STAQ1 



BPA3 4 



BPA4 



BPAS 



BPA6 



BPA7 R 



BPBO 



BPB1 



BPBP 11 



BPB3 1? 



BPB4 13 



BPB5 14 



BPB6 15 



BPB7 1fi 



BPCO 17 



:R354 



R385< 



'R319 



IP.318 



BPC1 1£ 



BPC2 19 



:C312 




"AAAr 
R394 



BPC3 Pf) 



BPC4 21 



BPCS P? 



BPCfi ?3 



BPC7 24 



R379 



-R355 



X300 



,ZXDP 



□ 



_26_ 



_2S_ 



62 BPDI7 



BPDIfi 



60 BPniR 



59 BPDI4 



58 BPDI3 



57 BPDI? 



56 BPDI1 



55 BPniO 



54 BPFI7 



53 BPFIfi 



52 RPFI5 



51 BPFI4 



50 BPFI3 



49 BPFIP 



48 BPFI1 



47 BPFIO 



;R380<R381<R382 



ALE 



R01 


111 


B02 


9 


R03 


8 


BQ4 


7 


BOS 


R 


ROfi 


5 


B07 


4 


Boa 


3 


RPFin 


?5 


BPFI1 


24 


BPFI2 


21 


BPFI3 


?3 


BPFI4 


? 


BPFI5 


26 


BPFIfi 


27 


, R377 


?0 


II wv /Rn 


2? 


1 



,0318 



/WR 



/RD 



5V D307 



38 TOT-TFST 



37 STAC1 



36 AIM-BIAS- CAP 



CRRNT-ENBL y^l-, 24VB 



24VB 



|CRRNT-CHCK> 



"►f 




yih 



R392 



C326 



R383 

-AW- 



D315 . 3322 D334 



C324 



Cd'23 



:R309 itD333 
D332 



03201/ 



RA309 



C325 



2 l3 U 15 



CA301 



BPDIO 



BPHI1 



BPDI2 



BPDI3 



BPDI4 



BPDIfi 



Q316 



BPDI5 



BPDI6 



BPDI7 



R378 




D327 3329 D335 



"R316 <R315 



<KJVR] 



- <M-VR| 



- <LGHT| 
- <THl1 



Q339 



y»~ 



BPD7 



/MR 



Q348 



'R397 



Q342 R321 

>W y-Wy 



GND-B 



Vy|y; <AEGIN| <M <GRID-VR| 

GND-B 



VR301 



'Q306 




KACOFFI 

Q333 ! 
i ,,.BPD6 



BPFI1 


3 


BPFI3 


4 


BPFI2 


7 


BPFI7 


8 


BPFI4 


13 


BPFI6 


14 


BPFI5 


17 


BPFIO 


18 


/WR 


11 


/HR 





,Q319 



-R340 



D1 Q1 
D2 Q2 



D6 Q6 
D7 Q7 
D8 Q8 



>CLK 
CLR 



2 BPF1 



5 BPF3 



6 BPF2 



9 BPF7 



12 BPF4 



15 BPFfi 



16 BPF5 



19 BPFO 



24VB 
>VR300 



COPYRIGHT© 1992 CANON «C. 



CANON NP-1550REV.il JAN.1992 PRINTED IN JAPAN (IUPRIUEAUJAP0N] 







Q317 








BPDI1 


3 


D1 
D2 
D3 
D4 
D5 
D6 
D7 
D8 

>CLK 
CLR 


Q1 
Q2 
Q3 
Q4 
Q5 
Q6 
Q7 
Q8 


V 


BPD1 


BPDIO 


4 


5 


BPDO 


BPDI4 


7 


R 


BPD4 


BPDI5 


R 


9 


BPD5 


BPDI7 


13 


1? 


BPD7 


BPDI6 


14 


15 


BPDfi 


BPDI3 


17 


16 


BPD3 


BPDI2 


18 


13 


BPD2 


/WR 


11 






/HR 


-If 





A-7 



DC CONTROLLER PCB (2/5) 



— f — T T — T — T T 1 — 
_ j C3|62 1 C360 | Cq58 | Ca|56 



c;s3 



Q312 



/MR 



BPF1 



BPFO 



/MR 



BPF2 



R323 



Q337 




BPDO 



A-8 



QH 



SER 
A 
B 
C 
D 
E 
F 
G 
H 



QH CLK 

INH 

SH/LD 



12 



JL3_ 



14_ 



Q332 




CIB1 



CC59 



C2 57 



C355, 



1HI"' 



R387 
-VvV- 



-o5V 



Q313 



JS. 



_L3- 



,14 



EN 



RS 
SIN 
SOUT 



LAT 
>CK 



QO 
Q1 
Q2 
Q3 
Q4 
Q5 
Q6 
Q7 



lfl_ 



_li 



_m 



RS 
SIN 
SOUT 



LAT 
>CK 



QO 
Q1 
Q2 
Q3 
Q4 
Q5 
Q6 
Q7 



iZ. 



10 



UNLATCH 



Q314 



>SCLKc 
SIN SOUT 
CS £ 



Q315 



BPAO 



RA308 
RA307 




Q328 



Q327 



Q329 



Q330 



Q331 



J Wr 



5V 



D308 



98765432 



X 



D309 



D310 



D311 



W06 



L 



Wr 



RA304 



RA305 
2 



D318 



D319 



D320 



D314 



D321 



D323 



C318 

LUD — *ff- 



D325. 



D324 
R327< 



R326 






TOT-TEST 



C317 



< TOT-TEST I 



- <KR1 | 
- < KR2 | 
- <KR3 | 
-<KR4] 
- <KR5 | 
- < KR6 I 



- < KR7 | 



- <KS2 | 

- <ksT| 

- <KS0 | 



- < LCSZ-C 



SORT-SB 



- < DF-SB | 



- C CCNTD | 
TCNT-PRES 



- < CSZ-' 



- < CSZ-2 | 



- < CSZ-1 | 



- < PDP2 | 

- < ENERGY-SAVING | 
JP300 



-<CTD] 

- < CPEP 

- < RDCI 
— ( MFPD | 



-O 
SW300 



Hi" 

)0 I' 



COPYRIGHT© 1992 CANOHMC. 



CANON KM550REV.O JAN.1992 PRINTED IN JAPAN (IMPHIME AUJAPON) 



DC C ONTR OLLER PCB (3/5) 



2 TCNT-PRES 




< DCBC | — » 



R 3/1 BPF4 

■wv 



COPYRIGHT© 1992 CANON INC. 



T. 1 992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



A-9 



DC CONTROLLER PCB (4/5) 



36VA 



:R341 



ZD300 



^pa 



,^w4^ 



777 



R337 
Q336 , M/l— 



Q335 



-Q319 

777 ! 



XT* 






STEP-ON 



~ W 






Q304 



▲ ZDB01 



:R330 z^C3C8 



C306 



777 



5V 

o 



SCHP 



>T 



-R350 >R349 >R348 



;,_ — I LHPV 

cjj&h --L— -^ r- 

fPDP1 > — ' 



C311 



5V 



C310 



C309 



RA302 



-T\^ 



| SORT-ACK> 

| df-ack) >- 
| sqrt-rxd') - 

| DF-RXD^ - 



R342 



R343 



R344 



R345 



7W^ 



WW^ 



RA301 =- 



1 Ui4( 



5V 

tlr 



C347 



C346 



C345 



C344 



RA303 



~^- 



< SORT-REC)} 



< SORT TXP} 

< df-txd} 



< DF-REQ | - 



Q310B 






< 



iQ310C 



Q310A 



10 



K~ 



BPCO 



.Q310D 



1 1 ii 



13 



12 



A -10 



R351 



R352 llt 

j — r= vW- 

w\a_ 



BPB6 



BPB7 



BPB4 



R353 



12 



Q305D 



13 



Q305C 



10 



y 

;c 

> 



BPB3 



BPB2 



BPB1 



5VO- 




777 



C307 



Q350 R331 

w- 




10 




BPB0 



BPC6 




Q351 R332 
MH 



Q353 R333 

M^- 1 



12 



Q354 R334 

AV — ' 



14 



8 Q308 



V V I 

C C N COMA 

I ? DRVA 



DRVA 
DRVB 



HOLD 



G G V V 
N N R R 
D D A B 



DRVB 
COMB 



:R335 



R338«^ i 

-m — 



w 



15 



— • < COM-A | 

1 — I — rooo 



: C327 ±- C328 

— 1 < PHA 



17 



X 



PHA\ | 
PHB | 
PHB\ I 



z|z C329 :±: C330 

1 < COM-B 



13 



:R329 <R328 



:R336 



-TQ307 



5V 5V 



-R346 >R347 



Q305A 



> 



Q305B 



BPA1 



BPC1 



BPCi2- ;-_, 



BPC3 



COPYRIGHT© 1992 CANON MC. 



CANON NP-1SS0HEVJ) JAN. 1992 PRINTED M JAPAN (IMPRIMEAUJAPON] 



5V 



(Q303) 
z!=C342 



5V 



(Q305) 
=!=C343 



5V 

(Q312) 
=j=C349 



5V 



(Q313) 
=bC350 



5V 



5V 



(Q314) 
4=C351 



(Q315) 
=|=C352 



5V 



(Q316) 
=!= C331I 



5V 

(Q317) 
=t C332 



5V 

(Q318) 
ztC333 



5V 

(Q319) 
=bC334 



5V 



24VB 



(Q320) 
:C348 



(J312) 
C339 

! 
I 



DC CONTROLLER PCB (5/5) 



5V 



GND-B 



GNCJ-B 



(Q310) 
:C354 



|36VA ) 
iGND-A ) 

Ignd; 



|5V 
|GND-By 



24VB; 



|COM-B^ 

|PMB^ 

|PMB\^ 

lCOM-A^ 

|PMA 

|PMA\, 



24VB, 



LNSD/ 



COPYRIGHT© 1992 CANON INC. 



J301 



J302 



1 
2 
3 
c|4 
5 
6 



J303 




J304 



< 1 



J305 




ZXDP) 



HTRD) 



|MMD) 
I ACOFF/ 



CURRENT-CHECK) 



jGRDON) 

|grid-vr3 

| HVTON) 
|24VB^ 

| acbonS 

|DCBC) 
IGND-B, 



lcsz-c; 



cszr 



CSZ2) 



CSZ3) 



CSZ4) 



CANON NP-1550REV.0 JAN. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



J306 



<2 



<4 
<5 



J307 



1 
2 
3 
4 
5 
<|6 
<7 



J308 




J309 



J310 



1 

2 

3 

<|4 



I TCNTD > 

1 24VB£ 

| PDP2D 

I GND!, 



J311 




| I 5Vj . 
I 24VBg 
I FM3D> - 



ENERGY-SAVING. 



KR3 



KR2 



CCNTD / 



CCNNt; 



J312 




J313 



<2 
<3 



<5 



<7 



J314 





J 




2 


; 




3 






4 






5 


' 




6 






7 
8 
9 
10 












11 






12 






13 






14 





K-VR, 



M-VR, 



|gnd 

|5V. 



SEG7, 



SEG6, 



SEG5, 



SEG4, 



SEG3. 



SEG2, 



SEG1 



SEGO, 



DG5; 



DG4; 



DG3; 



DG2, 



DG1 



dgo; 



|24VB; 
|DG6; 



gnd; 



thi; 



GND, 



[SCHP) 

Tiv; 



gnd; 



lhp; 



5v; 



AEGIN) 



AE^ 



IGND-B 
I 24 VB, 



J315 



1 

2 

3 

4 

5 

<|6 

<7 

<8 

<9 



J316 



<9 

< 10 

< 11 



J317 



sort-req; 



SORT-TXD, 



ISORT-SB 

Tgnd; 



sort-rxd; 



SORT-ACK, 



GND, 



GND, 



DF-ACK , 



DF-RXD , 



ignd; 

I DF-SB , 



df-txd; 



DF-REQ) 



Ithrhstr; 

I stac ; 
I tot-test; 

|5V 



I GND 
24VB; 



PAPER-FAN , 



J351 



1 
2 
3 
4 
<i5 



J352 



M301 



1 

2 

3 

4 

<|5 

<6 

<7 



A -11 



E. AE SENSOR CIRCUIT DIAGRAM 



A-12 




+24VA 



c7oa *= 




-&- 



COPYRIGHT© 1992 CANON INC. 



-O\j701 



GNOS „ 3 
O 3 j701 



R710 AE 
-W O z J70 1 



-O\j701 



CANON NP-155OHEV.0 JAN.1992 PRINTED IN JAPAN (IUPRIHE AU JAPON) 



F. AC DRIVER / DC POWER 
SUPPLY CIRCUIT DIAGRAM 



To 
DC 
CONTROLLER 



To 
DC 
CONTROLLER 




AC LINE 
COPYRIGHT© 1992 CANON WC. 



CANON NP-1SS0 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



A-13 



G. PRE-EXPOSURE LAMP CIRCUIT 
DIAGRAM ( 



A-14 



LA731 



LA732 



LA736 



LA733 



LA734 



LA737 



LA738 



R731 
-^A/V- 



R732 
— <w\< — 



^-O J731 PEXP 



-o J731 24V 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550 REV.O JAN. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



H. HVT CIRCUIT DIAGTRAM 




VCC=2I.5V 



COPYRIGHT© 1992 CANON INC. 



CANON NP-1550REV.il JAN. 199! PRINTED IN JAPAN (IMPRIMEAUJAPON) 



A-15 



I. LIST OF SPECIAL TOOLS 

Special tools which are required for servicing this copier (in addition to the standard tool. set) 
iare listed below. 



No. 


Tool name 


Tool No. 


Shape 


Code 


Application/remarks 


1 


Door switch 
actuator 


TKN-0093 


\Oj^C^^ Front door 


A 




2 


Spring scale 
(compression) 


CK-0054 


^ 


B 


• Measuring strength of 
cassette springs 

• Adjust scanner drive 
cable tension 


3 


Extension 
blades for 
pliers 


CK-0426 




B 


For removing grip rings: 
4 to 9 mm 



Note: Rank .,,. _.- - ; - -.- r ..^j.v.Tr.i 1 ;: 

A: Each service technician should 
carry one with him 

"B: A group"ef1i^.*SeWicet#ctti1ffci'ariS'; 

should share one., 
C: Each workshop shouW kf ip pne. i 



COPYRIGHT© 1992 CANONINC. 



CANON NP-1550 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON) 



A-17 



J. LIST OF SOLVENTS AND MATERIALS 



No. 


Material name 


Use 


Chemical formula, mix- 
ture ratio, etc. 


Source 


Remarks 


1. 


Ethyl alcohol 
(Ethanol) 

Isopropyl alcohol 
(Isoprapanol) 


Cleaning: 
copyboard 
glass, mirror, 
etc. 


C 2 H 5 OH 
(CHZa^CHOH 


Locally 


Flammable. 

Use in a well-ventilated area. 

Avoid breathing concentrated 

vapor. 


2. 


MEK 


Removing 
toner or oil 
stains 


CH 3 -COC 2 H 5 
Methylethyl ketone 


Locally 


Flammable. 

Use in a well-ventilated area 
and avoid breathing concen- 
trated vapor. 

Avoid contact with eyes or 
skin. 

Do not use of cleaning the 
drum, plastic molded parts, 
or corona wires. 


3. 


Heat-resistant 
grease 


Lubricating the 
drive 

mechanisms, 
e.g., copyboard 
driving gear, 
fixing drive gear, 
fixing assy, etc. 




CANON 


ToolNo.:CK-0427(500g 
can) (Equivalent grease can 
be used, but should be able 
to withstand 200 °C for 
extended periods of time.) 


4. 


Lubricating oil 
(low viscosity) 


Lubrication 
points: 
Scanner rail, etc 


ISO VG 68 oil 
ESSO Febis K68 
MOBIL Vactraoil No.2 
SHELL Tonna oil T68 


Locally 


Equivalent oil can be used. 
Tool No.: CK-0451 (100cc) 


5. 


Lubricating oil 
(low viscosity) 


Lubrication 
point: one-way 
clutch in pick-up 
control 
assembly 


ISO VG 220 oil 
ESSO Febis K220 
MOBIL Vactraoil No.4 


Locally 


Equivalent oil can be used. 
ToolNo.:CK-0524(100cc) 



A -18 



COPYRIGHT© 1992 CANON MC. 



CANON NP-1550 REV.1 SEPT. 1992 PRINTED W JAPAN (IHPRIME AU JAPON)